Insurer Ace buying Chubb in cash-and-stock deal valued at about $28.3 billion

Insurer Ace is buying The Chubb Corp. in a cash-and-stock deal valued at about $28.3 billion that will boost its international presence.

Chubb shareholders will receive $62.93 per share in cash and 0.6019 shares of Ace Ltd. stock.

Ace shareholders will own 70 percent of the combined business, with Chubb shareholders owning 30 percent.

The combined company plans to use the Chubb name and will have its main offices in Zurich, Switzerland, where Ace is based. Chubb's Warren, New Jersey, headquarters will contain a substantial portion of the headquarters function for the combined company's North American unit.

Both companies' boards unanimously approved the transaction, which is targeted to close in the first quarter of 2016. The deal still needs approval from Ace and Chubb shareholders.