Golden Gate Capital, a $12 billion private-equity firm, is backing a new reinsurance venture that will focus on the life, annuity and long-term care sectors.

Phillip J. Gass and Kostas Cheliotis will run the business, called Nassau Reinsurance Group, according to a statement Wednesday from the company. It has initial capital commitments of more than $750 million from funds managed by San Francisco-based Golden Gate.“Phil and Gus have a compelling track record of launching and leading profitable insurance platforms,” David Dominik, managing director of Golden Gate, said in the statement. They also “share our values and philosophy of building strong, sustainable businesses for the long term.”Gass and Cheliotis left Fidelity & Guaranty Life earlier this year. Its controlling shareholder, HRG Group Inc.,has saidit’s considering selling all or part of the insurer as part of a plan to overhaul what was once the investment vehicle for hedge-fund manager Philip Falcone.Nassau said the funds from Golden Gate will help it begin operations and fuel growth. They could also be used for acquisitions or reinsurance transactions.Golden Gate’s other investments include retailer Eddie Bauer and restaurant chain Red Lobster, according to its website.