Natixis Global Asset Management is quite possibly the largest asset manager you’ve never heard of.

With $753bn of assets under management as at the end of March, it is in the top 20 asset managers by size - 17th at the end of 2009, according to the most recent survey of global managers by Towers Watson/Pensions & Investment. Natixis staffers think it may have risen to 13th or 14th since then.