Royal & Sun Alliance has sold six million shares in Chubb Corporation, cutting its stake from 5.15% to 1.725%.
The shares in the US insurer were valued at £348m as at the end of December.
RSA said it would use the cash to buy non-equity investments.
The disposal was part of Royal & Sun's policy to hold a lower proportion of its shareholder's funds in equities and a higher proportion in less volatile assets.
