Tim Summers is used to operating in conflict zones, an experience that could come in useful in the coming weeks.

TNK-BP's chief operating officer is now the most senior former BP staff member remaining in Moscow after Robert Dudley's dramatic departure from Russia on Thursday night.

Mr Summers spent two years working in Colombia, where BP has an operation in the remote eastern province of Casanare, close to the border with Venezuela.

Marxist guerillas stalk the surrounding jungles and oilfields and pipelines, which are regularly attacked, are protected by government troops.

Conditions are not too much better in Bogota, where BP's country headquarters are located. The Colombian capital is one of the few cities in the world that is considered to be more dangerous than Moscow.

Mr Summers spent two years in Colombia from 2000 before a stint working for BP's exploration and production business in the North Sea.

Rising rapidly through the ranks, he was subsequently appointed as an executive assistant to BP's then chief executive, Lord Browne of Madingley, who sealed the TNK-BP joint venture agreement in 2003, before being offered the job in Moscow in 2006.

Mr Summers is expected to help to run the company and to act as a key channel of communication with Mr Dudley during his absence from Russia.

Amid an apparent campaign of harassment and intimidation from AAR, the consortium of four Russian directors that is BP's co- owner, and a series of mysterious raids and investigations by state officials, it is unlikely to be a job for the faint-hearted.

A certified chemical engineer who graduated from Manchester University in 1989, Mr Summers worked for BP for 17 years before making the move to Russia.

He also has experience working in Azerbaijan and the Caspian region, where BP has extensive oil production and pipeline operations.

Mr Summers is also a full member of the Institution of Chemical Engineers and the Institute of Materials, Minerals and Mining.