Private equity firms Thomas H. Lee Partners LP, Bain Capital LP, KKR & Co LP (>> KKR & Co. L.P.), KPS Capital Partners LP, and Sycamore Partners have indicated their interest in the sporting goods company, the people said. The sources could not be named because the talks are private. The auction is scheduled for Jan. 30.

British retailer Sports Direct International plc (>> Sports Direct International Plc) and Canadian pension fund Caisse De Depot et placement du Quebec have also submitted letters of interest, the people said.

Finnish sporting goods company Amer Sports, which makes Wilson sporting equipment, is interested in acquiring Performance Sports' baseball business, the people said.

Performance Sports filed for bankruptcy in the United States and Canada in October with a plan to sell itself.

The company's troubles highlight the challenges North American sporting goods manufacturers face in the highly competitive market. U.S. retailers Sports Authority and Golfsmith filed for bankruptcy earlier this year.

Performance Sports, Sycamore, Bain, Amer Sports (>> Amer Sports Oyj), Caisse, Thomas H. Lee, KPS and KKR declined to comment. Sports Direct did not respond to a request for comment.

A consortium led by investment firm Sagard Capital Partners LP and investment manager Fairfax Financial Holdings Ltd (>> Fairfax Financial Holdings Ltd) made the initial so-called "stalking horse" offer of $575 million for Performance Sports, the proposal the other buyers must top to win the auction.

Bidding for Performance Sports will start at about $601 million, clearing the initial proposal from Sagard and Fairfax plus other fees, according to bankruptcy court papers.

In October, Graeme Roustan, the former chairman of Performance Sports, told Reuters that he was talking with U.S. and Canadian private equity firms about submitting a bid for the company.

Roustan has challenged the Sagard deal, asking Canadian competition authorities to investigate it claiming there is a conflict of interest as Sagard's owner, Canada's wealthy Desmarais family, is an investor in rival Adidas AG (>> adidas AG) through its Power Corp of Canada (>> Power Corporation of Canada) vehicle.

Some private equity firms looking for operating expertise want to have Roustan on board, one of the sources said. Additional buyers may emerge before the Jan. 25 due date for bids, while others may join forces and combine their bids, the people said.

(Reporting by John Tilak and Jessica DiNapoli; Editing by Alan Crosby)

By John Tilak and Jessica DiNapoli