NEW YORK (Reuters) - KKR & Co LP (>> KKR & Co. L.P.) and Warburg Pincus LLC are among the private equity firms competing for Mitchell International Inc, a car and property claims software company that could fetch up to $1.5 billion, according to four people familiar with the matter.

Advent International Corp and Blackstone Group LP (>> The Blackstone Group L.P.) are also participating in the auction for Mitchell, which is in the second round of bidding, the sources said on condition of anonymity because the process is confidential.

Owned by buyout firm Aurora Capital Group, Mitchell has annual earnings before interest, tax, depreciation and amortization (EBITDA) of about $90 million, the sources said.

Aurora, Warburg Pincus, Advent International and Blackstone declined to comment. Mitchell and KKR did not respond to a request for comment.

Founded in 1946, San Diego, California-based Mitchell provides information and software services to insurance companies and collision repair facilities, which rely on the company's information to estimate labor times and the cost of replacement parts.

Joined by investors that included General Electric Pension Trust (>> General Electric Company), Aurora acquired Mitchell in 2007 from private equity peer Hellman & Friedman LLC for an undisclosed amount.

The North American market for software and services designed to automate the auto insurance claims process is dominated by a few players - Mitchell, CCC Information Services Inc, and Solera Holdings Inc (>> Solera Holdings Inc) - according to Standard & Poor's Ratings Services.

In January, Leonard Green & Partners LP, another buyout firm, acquired CCC from Investcorp , one of the Middle East's largest private equity houses, for more than $550 million.

Aurora has hired Goldman Sachs Group Inc (>> Goldman Sachs Group Inc) to explore a sale of Mitchell International, people familiar with the matter told Reuters in April.

(Reporting by Greg Roumeliotis and Nadia Damouni in New York; Editing by Leslie Gevirtz)

By Greg Roumeliotis and Nadia Damouni