Arthur Beesley, Senior Business Correspondent, charts the year's winners and losers

Riverdeep's supersized reverse takeover of grand old Boston publisher Houghton Mifflin brought Barry O'Callaghan to the front of the pack in a year in which the largest deals were quantified more in billions than millions.

The $4.95 billion (€3.77 billion) transaction is not without risk, but O'Callaghan stands to receive the lion's share of a shareholding worth at least $132 million free of charge under a "promoter and management incentive" clause. If O'Callaghan achieves that, he is an undisputed winner.

In a golden period for many prominent business people, financier Dermot Desmond realised a massive profit when he sold London City Airport for €1.1 billion. Desmond dismissed the first report of the Moriarty tribunal, which said it could not accept evidence he gave about payments he made to the Charles Haughey.

Another big-timer, Michael Smurfit, brought the Ryder Cup extravaganza to the K-Club. Packaging group Smurfit-Kappa is widely expected to float in 2007, as is Denis O'Brien's rapidly expanding Caribbean mobile group Digicel. O'Brien stepped down from the role of deputy governor at Bank of Ireland to concentrate on that process. O'Brien will feature in the second report of the Moriarty tribunal, which examined the award of the State's second mobile licence to Esat Digifone.

For other business people, there was much to dread in 2006. Martin O'Rourke of health insurer Bupa had a grim time of it with an unsuccessful High Court challenge to the risk equalisation scheme. Bupa now plans to leave the market. In addition, Oisín Fanning's Smart Telecom came perilously close to collapse while the cheerless Corrib gas project mired oil giant Shell in protest and controversy.

However, the biggest losers by far were the multi-millionaire Bovale brothers, Mick and Tom Bailey. The boys had a high time for years, notwithstanding Mick's corrupt payments to George Redmond and Ray Burke. The rot finally caught up with them in 2006 when they made a €22.17 million tax settlement, the State's largest.

Weeks later, Mick made an appearance in the Fianna Fáil tent at the Galway races.

The Revenue inflicted pain elsewhere in the construction sector, which was the target of a special audit campaign. In its first five months, the effort yielded more than €50 million in addition tax and penalties.

Not that Brian Cowen was short of cash. Record tax returns helped the Minister for Finance form a feel-good 2007 Budget, the last before the election.

Still, a relentless round of interest rate increases from Jean Claude Trichet and his pals at the European Central Bank took their toll on borrowers.

After years of dithering, the Government managed to sell off the Great Southern hotel chain for €265 million with multi- millionaire businessmen Gerry Barrett and Bernard McNamara prominent among the buyers. But if the earth did not move when the State made its long- delayed exit from the hotel sector, the Aer Lingus privatisation was entirely different.

Bertie Ahern always appeared reluctant to go down that road, but went along in the end with Martin Cullen's flotation plan. Then, within days of the stock market listing, Michael O'Leary of Ryanair pounced with an unsolicited bid for Aer Lingus.

Queue withering criticism from Siptu and stakebuilding by the airline's Employee Share Ownership Trust (Esot), its pilots' pension fund, a group of pilots called Tailwinds and Denis O'Brien.

O'Leary did not win out, at least for now, but it's hard to characterise Aer Lingus chief Dermot Mannion as a winner in this particular affair.

Meanwhile, the Government is poised conclude a buyout of the West-Link toll bridge from National Toll Roads (NTR). With price tag of €600 million on the bridge, NTR is primed for a major gain early in 2007.

So too is Michael Fingleton of Irish Nationwide, who is preparing to sell the institution.

Irish groups were sellers and buyers on a grand scale in 2006.

At CRH, Liam O'Mahony et al spent more than €1 billion on the acquisition of Atlanta asphalt group Apac, its bigger deal of the year and one that came in advance of a foray into China.

There were other buyers. Aidan Heavey of Tullow Oil forked out €865 million for its Australian rival Hardman Resources. Owen Killian at IAWS spent €448 million on the acquisition of US baker Otis Spunkmeyer, its biggest deal.

Leonard Ryan and Michael O'Rourke made huge strides with Setanta Sports. The pay television group won live Premiership soccer rights in Britain at a cost of €574 million, Irish screening rights for €40 million and British and Irish rights for PGA golf at a cost of some €150 million.

Meanwhile, London private equity fund Doughty Hanson acquired TV3 for €265 million.

The most prominent management buy-out (MBO) was at Davy Stockbrokers, where Tony Garry, Kyran McLaughlin and Brian Davy led a group of 110 staff who paid €316.55 million to take control of the broker from Bank of Ireland.

An even larger MBO took place at place at Spar and Mace franchise owner BWG, where Leo Crawford, John O'Donnell and John Clohisey bought out the Cognetas European Fund in a €390 million deal.

On the sell side, the latest in a long line of ownership changes at Eircom saw Australian fund Babcock & Brown pay €2.36 billion for the former State telephone company which was the subject of an abortive bid from Swisscom in 2005.

The deal heralded yet another bonanza for Eircom's executive directors, whose investment in mobile player Meteor started to come good this year.

The really big winner this time round was Con Scanlon of the Eircom Esot, which increased its stake in the business to 35 per cent from about 20 per cent.

Sir Anthony O'Reilly, Dr Phil Nolan, Peter Lynch and David McRedmond each left Eircom as Rex Comb, Pierre Danon and Rob Topfer entered the scene. The newcomers were swift to cut off Smart Telecom's network connection, a move that severely inconvenienced 45,000 Smart customers. Fanning had already resigned. After days of grave doubt over Smart's viability, its biggest single shareholder Brendan Murtagh came forward with a proposal to refinance the troubled company.

Meanwhile, Sir Anthony's Independent News & Media (IN&M) had a setback in Australia when it withdrew a A$3.8 billion (€2.3 billion) approach with private equity house Providence for media group APN. IN&M is expected to make a second stab at that deal next year.

Entrepreneurs who took an exit from their companies in 2006 included Tipperary businessman Michael Costello, who sold his generic drug company Pinewood to Indian group Wockhardt for €113.98 million. Kerry businessman Jerry Kennelly made €110 million when he sold his digital imaging business Stockbyte to the Getty family.

Liam Young and Eddie Kerr, founders of directory inquiries company Conduit, realised €30 million after the sale of the company for €90 million to Bahrainhi bank Investcorp SA and inquiries group InfoNXX. Another Bahraini investment group, Arcapita, acquired Northern Ireland electricity company Viridian for £1.62 billion (€2.4 billion).

Just before Christmas, Austria Telekom bought out Seán Melly and Bernard Somers from eTel, the central and east European telephone company, in a deal worth more than €90 million.

Nearer home, west Cork group SWS went to Ion Equity for €110 million. Ion's affiliate Topaz bought out the Statoil's Irish filling station and oil distribution business for some €285 million.

This deal, which came in the year after Topaz bought Shell's filling station network, was inadvertently cleared by the Competition Authority when it missed the deadline to impose restrictions on the takeover.

On a happier note for the authority, the anti-trust body secured criminal convictions this year against certain members of a home-heating oil cartel in Galway city and county.

Roches Stores sold out to Debenham's for €29 million in a deal that saw Roches' iconic outlets on Henry Street in Dublin and Patrick Street in Cork change hands for the first time since the 1920s.

The Roche family will receive rents of almost €18 million a year on the properties in the chain.

The property part of the Roches deal was indicative of the continued strength of Irish property generally, a market in which investors spent some €3 billion in 2006. But with big players such as Derek Quinlan, Treasury Holdings, David Arnold and the Cosgrave brothers on the march in Britain, Germany and further afield, international investments were dominant in 2006. The Irish spent no less than €8.1 billion abroad, according to CB Richard Ellis Gunne, more than twice as much as at home.

In 2005, Tiernan O'Mahony missed out on the top job at Anglo Irish Bank to David Drumm. Just a year later, O'Mahony has reversed this setback in spectacular fashion. After leaving the bank, he raised €145 million from private investors for his finance company International Securities Trading Corporation. This business made pretax profits of €6.5 million in its first year. Its share price on a grey market stood this week at €325, more than three times the value of the original €100 per share placing.

At Allied Irish Banks, meanwhile, past misdeeds came to the fore on two occasions. The Moriarty tribunal said the State's largest financial institution gave an "indirect payment" of some IR£393,000 to Mr Haughey when it forgave some of his debts after he became taoiseach in 1979.

Earlier, AIB said new investigation discovered that customers of the bank were overcharged by more than €21 million in the late 1980s and early 1990s. That left AIB with a bill for €31.6 million, including interest, bringing its total financial liability from the overcharging scandals to €65.8 million.

What is is more, AIB did not discipline any staff after the inquiry.

Suffice to say to that the overchargers weren't the losers.