Trefgarne is stationed within the oil group's London press office, and reports to senior vice-president of group media Roddy Kennedy.
‘George is a good guy and a very able writer, and it's very good to have him,' said Kennedy, adding that Trefgarne's duties would include writing speeches for group chief executive Lord Browne, as well as day-to-day media relations.
Trefgarne left The Sunday Telegraph in May after seven months as City editor. He worked at the Telegraph Group for ten years, which included stints as economics editor and comment editor. He has recently been a columnist for the Daily Mail and The Spectator.
BP is under scrutiny for its environmental practices. Earlier this year, a corroded transit pipeline at the firm's Prudhoe Bay oilfield in Alaska caused a spillage, and part of the field was shut down in August.
Kennedy reports to group vice-president of corporate comms and external affairs Mark Ware, who also oversees director of brand and comms Anji Hunter.