American International Group, the US insurer, has bought a 4.3% equity stake in Aspect Capital, the $2.5bn (€2.1bn) London hedge fund manager in which Man Group holds a 25% stake.

AIG has also taken an option to purchase 8% more of Aspect. It did not disclose the financial terms of the transaction, but said it was investing $75m in funds managed by Aspect. It has a second option to provide $125m of additional seed capital for Aspect's future investment funds.