Bermuda-based insurer Endurance has raised $1.2bn (£823.2m) of capital to supply underwriting capacity in commercial property and casualty insurance and reinsurance markets.
The company, whose major sponsors are Aon and Zurich Financial Services, will begin underwriting immediately.
Endurance chairman, president and chief executive officer Kenneth LeStrange said: "There is a significant demand for underwriting capacity as a result of the hardening market and the aftermath of 11 September.
"Endurance is prepared to meet that demand and is committed to this market. We are well capitalized and have an excellent team in place that is prepared to do business."
Endurance will focus on six main lines of insurance: property insurance and per risk reinsurance, property catastrophe reinsurance, excess workers' compensation reinsurance, aviation liability insurance, directors and officers (D&O) insurance and excess general liability insurance.
It plans to offer capacity of $5m (£3.4m) to $30m (£20.6m) per programme.
Apart from Aon and Zurich Financial Services, major investors in Endurance include Capital Z Financial Services Fund II, Thomas H. Lee Partners, Texas Pacific Group, and Perry Capital.
The company, a Class 4 Bermuda insurer, raised the $1.2bn through a private placing, which closed on Friday, 14 December 2001.