A California-based clothing manufacturer is suing Jessica Simpson for $100 million, claiming she breached their contract by failing to support lines of apparel she developed with the company.

Tarrant Apparel Group (TAG) of Los Angeles says in court papers that an agreement it signed in December 2004 with Jessica Simpson Brand Management LLC lets it use Simpson's name to make, sell, market and distribute women's sportswear.

TAG's court papers say that same three-year agreement, which has a two-year renewal option, requires that "Ms. Simpson shall be actively involved in promoting (TAG's) products, whether requested or not" by the company.

The singer also must "publicly wear/display or use the products, particularly at events, shows and appearances," say papers filed last week in Manhattan's state Supreme Court. The clothing brands are Jessica Simpson, Princy, and JS by Jessica. A fourth brand, scheduled for market in January 2007 is Sweet Kisses.

TAG says it has already paid Simpson $2.2 million with another $1.6 million guaranteed as a sales royalty for 2004 and 2005 and an additional $4.4 million guaranteed for the remainder of the contract.

The company accuses Simpson of breaching the multimillion-dollar deal by failing to wear or be photographed in the duds and has even named another brand of blue jeans as her favorites.

Simpson's lawyer, Jed Ferdinand, said: "She denies it. It's absolutely untrue. That's what the evidence will show, and she will vigorously fight the lawsuit."

Ferdinand and TAG's lawyer, Jack Gordon, said the parties had tried to resolve the dispute but negotiations failed.

"We are saddened that relations deteriorated to the point where litigation became necessary," Gordon said. "The fact is that celebrity branded apparel requires the support of the celebrity."

Simpson, 25, and her husband, singer Nick Lachey, 32, announced their separation on Nov. 23, saying they had decided to part ways after three years of marriage ¡ª and months of rumors, denials and salacious magazine covers.

Simpson's 2004 album, "In This Skin," went platinum, and she released a Christmas album last year.