* HPS, Madison Dearborn are leading investors
* New group buying Nevada for 250 mln pounds
* New group reviewing structure, may refinance existing debt (Adds details, background)
By Simon Jessop and Carolyn Cohn
LONDON, May 9 (Reuters) - The majority owners of insurance broker Towergate, which restructured its debt two years ago, said on Tuesday they planned to bring together their various UK broking businesses into a new holding company which may issue new debt.
HPS Investment Partners became Towergate's largest shareholder in 2015 after Towergate sold itself to its senior secured creditors as part of a deal to slash its debt pile.
Madison Dearborn Partners became the firm's second largest shareholder last year.
The two private equity firms said in a statement they would look to consolidate the group's capital structure in the loan and bond markets, including through refinancing existing debt. They said they would give more details of the plans in the third quarter.
Joining Towergate under the new structure would be Autonet, a van insurance broker, private medical insurance broker Chase Templeton, and general insurance broker Ryan Direct Group. All would operate independently under existing management.
A fifth company, Lloyd's Of London speciality insurance broker Price Forbes, would also join the new holding company, they added. The new holding company, called KIRS, would be renamed in the third quarter.
KIRS is buying Nevada, the holding group for Autonet and Price Forbes, for 250 million pounds ($323.25 million), the investment groups said.
Investment firms KKR and Bain Capital are also minority shareholders in Towergate and are expected to remain invested in the new group, a spokeswoman said.
The investment groups said John Tiner, Towergate's chairman, had been appointed chairman of the new enlarged group with its chief executive David Ross taking the same role at the new group.
"Today's announcement demonstrates the tremendous confidence our major shareholders have in the businesses we are bringing together and the opportunities for further expansion," Tiner said in the statement. ($1 = 0.7734 pounds) (Editing by Lawrence White, Greg Mahlich)