The process through which Eircom may be sold is only just beginning and it may be weeks or months before it reaches a conclusion.

At some stage, if a deal is to go ahead, shareholders will be asked to decide on one or more offers for the company.

A bidding battle can be very like a game of "cat and mouse", with players trying to gain strategic advantage over their competitors through the timing of their moves. But once the formal process starts it has to operate under the rules of the Irish Takeover Panel (ITP), which effectively sets out a timetable for the process.

Eircom with its advisers, Goodbody Corporate Finance and Merrill Lynch, set close of business yesterday as its deadline for offers. But under ITP rules, potential bidders are not bound by this date and could join a bidding battle at any stage.

The Eircom board now has to examine the proposals it has received. Its options depend on the proposals: all of the offers could be too low and the board could reject them or give the bidders a number of days to come back with a better price; one offer could be the most attractive and the board could decide to enter exclusive negotiations with this bidder; or the board could look for clarification from all the bidders on various points in their proposals.

ITP rules come into play when a bidder makes an announcement of firm intent to make an offer for Eircom.

The Eircom board could recommend that shareholders accept the offer - as in the sale of Eircell to Vodafone - or it could state that, in its view, the offer does not represent value for shareholders.

Once a bidder makes the announcement of firm intent to make an offer under ITP Rule 2.5, he has 28 days in which to make the offer, though this is likely to happen much more quickly. This rule applies whether the offer has board recommendation or whether it is hostile - one the board has declined to recommend.

Making the offer is legally defined as posting the offer document to shareholders. That document must set out full details of the offer and will invite shareholders to indicate their acceptance of the offer - usually through the inclusion of an acceptance card or form that shareholders in favour of the deal should return to the address indicated. Posting day is then taken as day zero in the formal ITP timetable, which could span up to 81 days.

The first significant staging post in the ITP timetable is Day 21, the first closing date. This means that an offer or must leave their offer open for 21 days or that at day 21 a bidder could withdraw their offer. Any move to withdraw a bid must be cleared by the ITP.

Approval would be given where, for example, the bidder had received only a very low level of acceptances from shareholders.

The next important day is Day 42. This day is important for shareholders because they can withdraw their acceptances up to this day if the bidder has not gone unconditional on acceptances. This means that where a bidder has set a condition as to the level of acceptances it requires to proceed with its offer - acceptances representing more than 50 per cent of the shares in issue is usual in takeover bids but it could be as high 80 per cent - that offer can only be declared unconditional on acceptances when shareholders representing that level of shares have accepted the offer.

When an offer is declared unconditional on acceptances, the shareholders who have accepted are then locked in to the deal. A bid must be declared unconditional as to acceptances within 60 days of the start of the process.

Effectively, once a bid is declared unconditional on acceptances no other bidder can trump it because it has achieved the required level of acceptances.

Offers must go wholly unconditional within 21 days of going unconditional on acceptances.

This is the ITP timetable where one bidder is involved. But the process becomes more complicated if other bidders enter the process - and they can at any stage.

Once another bidder becomes involved, the ITP calendar goes back to day zero for both bidders from the date the second bidder's offer document is posted to shareholders. If a third bidder emerged the calendar goes back again to day zero for all bidders. Competing offers could be made for Eircom at any time and, because the board is obliged to get the best deal for shareholders, all offers must be examined. The rationale behind the ITP rules is that, if a legitimate bidder wants to make an offer for a company, shareholders should be given an opportunity to consider it.