Chubb

(CB) - Get Report

has confirmed reports of its involvement in negotiations to acquire British insurer

Hiscox

.

Officials for Chubb admitted the insurance company had "made an approach" to Hiscox. The deal could include a cash offer by Chubb for about 73% of the Hiscox shares it doesn't already own.

Chubb, which is based in Warren, N.J., valued Hiscox at about $2.50 a share, or 170 pence, but that could change. Chubb ended

New York Stock Exchange

trading up $1.44, or 2%, to $73.38.