TOKYO (Reuters) - U.S. private equity fund KKR said on Monday it sent a letter to Fuji Soft asking it to make a court filing to stop what it said was Bain Capital's violation of a non-disclosure agreement amid Bain and KKR's acquisition battle for the software maker.

In the letter, KKR asked Fuji Soft to file an injunction to halt Bain Capital's "continued breach of its non-disclosure agreement".

KKR and Bain are trying to buy Fuji Soft in competing tender offer bids worth as much as $2 billion.

Fuji Soft's board has come out in support of KKR's lower bid and demanded that Bain destroy the confidential information it compiled during due diligence.

Bain has said this disregarded the interests of shareholders and that it wanted to continue using the information to launch its tender offer. Fuji Soft's founding family has said it supports Bain's bid.

Fuji Soft and Bain did not immediately reply to Reuters' requests for a comment.