Two of the biggest French asset management companies have expanded overseas this week, with one acquiring a business in the US and another opening a new office in the Middle East, as the country's fund managers continued to grow last year despite the credit crunch, according to a new report.

Natixis Global Asset Management, the funds arm of the French corporate and investment bank Natixis, bought the US investment manager Gateway Advisors earlier this week and has also reorganised its marketing structure.