UPDATE 1-Par to pay $45 mln, end US probes over AIDS appetite drug

* Payout split between fine, forfeiture

* Par challenged over marketing of appetite drug

* TPG Capital bought Par in September

March 5 (Reuters) - Par Pharmaceutical Inc has agreed to pay $45 million to settle federal criminal and civil probes over its marketing and sale of a drug to treat appetite loss in AIDS patients, a spokesman for federal prosecutor Paul Fishman in New Jersey said on Tuesday.

The generic drug company is expected to plead guilty to a criminal misdemeanor charge at a Tuesday hearing before U.S. Magistrate Judge Madeline Cox Arleo in Newark, New Jersey, the spokesman said. Par's payment will be divided equally between a fine and a forfeiture, the spokesman said.

Par, based in Woodcliff Lake, New Jersey, was purchased in September by private equity firm TPG Capital LP for $1.9 billion.

The company has been the subject of a U.S. Department of Justice inquiry into its marketing and sales of the drug Megace ES, which is intended to improve the appetites of HIV and cancer patients.

Tuesday's accord encompasses a civil "whistleblower" lawsuit alleging that Par engaged in illegal off-label marketing of Megace ES, according to Timothy McInnis, who brought that case.

Par did not immediately respond to a request for comment.

On Monday, Par said in a filing in the Washington D.C. federal court that it had been "close to finalizing" a resolution of several pending investigations and litigations.

Last September, the company said it had set aside $45 million as its "best estimate" for a potential global settlement regarding the inquiry.

Fishman is expected to hold a news conference later Tuesday to discuss the Par settlement.