Formerly head of international at Morgan Stanley, he was a special adviser on business and investment to former British prime minister Rishi Sunak, and has been a member of the House of Lords since 2024.

[2] Petitgas retired from Morgan Stanley in November 2022, but stayed on a senior adviser to the company.

[3] In April 2023, British prime minister Rishi Sunak appointed Petitgas a special adviser on business and investment while Sunak sought to increase business investment and deliver on the government's economic pledges.

[10][11] With his wife Amanda, Petitgas owns the historic manor of Bosham in West Sussex, comprising 2,230 acres (900 ha) of Chichester Harbour and its moorings.

[13] Nominated by Sunak for a life peerage,[10][14] he was created Baron Petitgas, of Bosham in the County of West Sussex, on 7 March 2024.