Like a row of eager schoolchildren, Lord John Browne's successors yesterday sat in the front row of the company's conference room and listened as their chief executive announced for the first time that without a shadow of doubt he would be leaving BP at the end of 2008.

That leaves the handful of hopefuls who run BP's various businesses a final 18 months to jockey for position.

The man to woo is undoubtedly Peter Sutherland, BP's chairman, who illustrated his authority yesterday by achieving what he had set out to do when he pulled aside his chief executive on Friday and demanded he make clear that his retirement date would be the end of 2008.

Mr Sutherland himself is expected to leave a year after Lord Browne, once a successor is safely in place, people close to the chairman said. The chairman himself was not commenting yesterday to the Irish or British media.

He will almost certainly pick a candidate from within BP, in part because there are few outside executives able to run the world's second-largest energy group by market capitalisation and also because BP has spent several years grooming five hopefuls, all of whom already run huge businesses in the own right.

The candidates include John Manzoni, head of refining and marketing and possibly the closest to Lord Browne's mould; Tony Hayward, the youthful looking head of exploration and production who is tipped as a favourite; his deputy Andrew Inglis; Iain Conn, chief of staff; and the jovial Robert Dudley. Mr Dudley was the only man not in the room, instead he was in Moscow, busily steering TNK-BP, the company's Russian joint venture, through the political uncertainties thrown up by the Kremlin in the past three years.

The next chief executive's task will be more daunting than dealing with Russia's president.

The industry faces significant challenges and international oil companies are finding it more and more difficult to grow as oil-rich countries jealously guard the world's remaining reserves of oil and gas.

But he will inherit a company in much better shape than it was when Lord Browne took over more than a decade ago.

Tony Alves, analyst at brokers Peel Hunt, said Lord Browne had led during a period of huge change in the oil industry and would leave the company in good shape.

Given the size of BP, Mr Alves said few investors would consider not holding shares on the basis that Lord Browne was or was not at the helm.

It is clear investors wanted above all a smooth succession at BP.