By Joyce Lee
SEOUL (Reuters) - Carlyle Group, Bain Capital and auto supplier Mahle have each submitted preliminary bids to buy a 70% stake in South Korea's Hanon Systems worth an estimated 6.6 trillion won ($5.8 billion), the Korea Economic Daily reported.
The combined stake in Hanon, a maker of automotive air conditioning systems, has been put up for sale by local private equity firm Hahn & Company and Hankook Tire & Technology Co Ltd, the newspaper said, citing unnamed investment banking sources.
Hanon Systems said in a regulatory filing on Wednesday that nothing has been decided.
A spokesperson for Germany's Mahle declined to comment. Representatives for Carlyle and Bain did not immediately respond to requests for comment.
The newspaper said France's Valeo had also submitted a preliminary bid but the auto supplier denied that it had.
Hanon Systems, the world's second-largest supplier of auto thermal management systems, reported revenue of 6.9 trillion won and operating profit of 315.8 billion won last year.
($1 = 1,135.0600 won)
(Reporting by Joyce Lee; Additional reporting by Gilles Guillaume in Paris; editing by Louise Heavens and Edwina Gibbs)