Private equity firm Lone Star Funds said on Monday it is seeking a court order to terminate its roughly $400 million purchase of Accredited Home Lenders Holding Co, saying the subprime mortgage lender has not met the conditions required to close.

San Diego-based Accredited had sued Lone Star on August 11 in Delaware Chancery Court, seeking to force it to complete the $15.10 per share buyout.

Lone Star said Accredited's only possible contractual remedy is a $12 million breakup fee. It said it is also seeking court declarations that Accredited has breached "numerous" other obligations to Lone Star.

Accredited shares closed Monday down 31 cents at $6.44 on the Nasdaq.