Winters is setting up the venture, to be called Renshaw Bay, with Rothschild's London-listed RIT Capital Partners
The launch ends Winters' brief absence from the frontline of the financial services industry after quitting JPMorgan in 2009 following a falling out with Chief Executive Jamie Dimon.
Winters is one of five members of the UK government's Commission on Banking due to make recommendations on the future structure of the industry in September.
He will initially own 50 percent of the Renshaw Bay business, with the balance owned by RIT and Reinet, the Luxembourg-listed investment vehicle.
Our objective is to build a global alternative asset management and advisory business ...for our founding shareholders as well as other sophisticated investors who value our strong focus on risk management and alignment between investors and investment managers, Winters said in a statement.
Winters, RIT and Reinet are expected to plough substantial sums of their own capital into Renshaw's funds and investment vehicles and may also seek to build out or acquire investment management capabilities after achieving authorization from Britain's Financial Services Authority.
(Reporting by Sinead Cruise; Editing by Erica Billingham)