US-based O’Shaughnessy Asset Management, a quantitative investment manager, has announced that it has completed its exit from Bear Stearns Asset Management, a unit of Bear Stearns, the stricken US bank recently acquired by JPMorgan.

In becoming completely independent from all operational links with Bear Stearns, O’Shaughnessy Asset Management becomes a formally independent business with over $9 billion in assets under management, making it one of the largest asset managers in the US.

At Bear Stearns, James O’Shaughnessy, chairman and chief executive of OAM, saw the business’s assets rise from under $1 billion in 2001 to over $9 billion in 2007.

OAM is based in Connecticut and delivers a range of equity portfolios to institutional investors and the high net worth clients of financial advisors.

It also serves as a sub-advisor to a family of mutual funds through the Royal Bank of Canada.