Lehman Brothers Holdings Inc is being sued by two former clients for more than $190 million, alleging the failed bank deceived them about the market for auction-rate debt.

Western Digital Corp and Ceradyne Inc filed the suits on Tuesday in Lehman's bankruptcy case, claiming to have suffered a devastating financial impact induced by (Lehman's) deceptive sales practices with respect to auction-rate securities, a supposedly liquid financial product.

The companies allege that Lehman knew, but failed to inform them, that the securities were not supported by a broad, fully-functioning market.

Lehman spokeswoman Kimberly Macleod declined to comment.

A spokesman for Lake Forest, California-based Western Digital also had no comment, and a spokesman for Costa Mesa, California-based Ceradyne could not immediately be reached.

The firms are seeking to recoup funds they invested in asset-backed securities, as well as punitive damages.

Auction-rate debt has rates that reset in periodic auctions, but some brokerages told investors the debt was as good as a cash substitute. When the market froze, many investors found themselves saddled with the debt.

(Reporting by Lilla Zuill, Editing by Ian Geoghegan)