Allen & Overy (A&O) will lose one of its biggest names as global projects, energy and infrastructure head Graham Vinter moves in-house to become BG Group's new general counsel.
Vinter, a partner at the magic circle firm for nearly 20 years, announced his departure for BG, an A&O client, on 24 October.
A week before the announcement A&O was topping the Dealogic global PFI/PPP tables for the first nine months of 2007, working on 43 deals worth $14.78bn (£7.22bn).
Vinter told The Lawyer: "Without doubt, my greatest achievement has been building and nurturing the team."
Vinter is a blue-chip name in the market. Freshfields Bruckhaus Deringer head of PFI/PPP Nick Bliss commented: "He's had a fantastic career at A&O and has been the top man of a market-leading team."
Another rival said: "I'm competing with A&O. The idea that Graham Vinter isn't competing anymore isn't going to make me cry."
Despite the group's standing in the market, Vinter was one of the few projects partners, who bill in dollars rather than pounds, who did not see his points diminish last year following a strategic review.
Vinter will be replaced as global head by partner Anne Baldock, who also happens to be his wife. Her priorities, she said, are to ensure "business as usual".
Target jurisdictions are Saudi Arabia and Abu Dhabi, where the firm has recently opened offices.
Other rising stars in the practice include partners David Lee and Andrew Fraiser. In China, where the team has had great success, rivals point to Shanghai managing partner Simon Black.
Meanwhile, BG, which has a 100-strong global legal team, historically instructs A&O, Herbert Smith, Linklaters, Shearman & Sterling, Skadden Arps Slate Meagher & Flom and Vinson & Elkins on projects and corporate work.
"Of all the parts of the old British Gas, it's the largest and the most dynamic," said Vinter.
He did concede that there was an issue with instructing his wife on matters. "Of course, I've got to be squeaky clean," he said. "Frankly, I know that if ever things got critical I know one firm, and the personalities within it, particularly well."