Specialty and surplus lines insurer StarStone U.S. Holdings Inc. announced new executive management and a $630 million capital injection on Thursday.

In addition, StarStone Group CEO John Hendrickson has stepped down, Bermuda-based parent company Enstar Group Ltd. said in a statement.

Private equity firms Aquiline Capital Partners LLC, Dragoneer Investment Group and SkyKnight Capital LP will invest $610 million in StarStone U.S. and the firm’s management will invest $20 million, which will increase the insurer’s capital to over $850 million, the statement said.

In addition, Enstar units will provide loss portfolio and adverse development reinsurance cover for StarStone U.S., the statement said.

Jeff Consolino was named CEO of StarStone U.S. Mr. Consolino most recently was chief financial officer of American Financial Group Inc., the Cincinnati-based parent of Great American Insurance Group. Prior to joining American Financial in 2012, he was president and chief financial officer of Validus Holdings Ltd.

StarStone’s U.S. operations were previously headed by CEO Linc Trimble. An Enstar spokeswoman declined to comment beyond the company statement.

In addition, industry veteran Ed Noonan was named executive chairman of StarStone U.S. Mr. Noonan, who headed Validus until its sale to American International Group Inc. in 2018, joined London-based StarStone Group as chairman last year.

The changes mark “a pivotal moment” for StarStone U.S. as the insurer seeks to grow its excess and surplus lines business, Dominic Silvester, CEO of Enstar, said in the statement.

“StarStone U.S. will work with Enstar, as opportunities warrant, in our ongoing acquisition activities,” he said.

StarStone U.S. will also have a new board of directors, including Steve DeCarlo, former CEO of wholesaler AmWins Group Inc., the statement said.

StarStone U.S.’s operations include StarStone Specialty Insurance Co., its E&S unit, and StarStone National Insurance Co., an admitted insurer. In addition, the insurer writes U.S. business through StarStone’s Lloyd’s of London syndicate.

The U.S. business wrote about $458 million in premium in 2019, composed of 44% excess casualty, 26% workers compensation, 12% management and professional liability, 7% marine, 3% health care and 8% other, according to the company’s website.

Mr. Hendrickson was named group CEO of StarStone Group in 2018, also joining from Validus.

StarStone was founded as Torus Insurance Holdings Ltd. in 2008. Enstar bought the insurer in 2014 and rebranded it as StarStone in 2015.