(Reuters) — Forty-six U.S. state attorneys general will seek to expand a lawsuit alleging price fixing of generic drugs to 18 companies and 15 medicines on Tuesday, including Novartis A.G.'s generic unit Sandoz and India-based Sun Pharmaceutical Industries Ltd., people familiar with the matter said.

The original complaint, being litigated in federal court in Pennsylvania, describes an industrywide conspiracy in which companies divide up the market as a way to push up prices.

In the amended complaint, the number of generic drug manufacturers named goes from six to 18, including Endo International P.L.C.'s unit Par Pharmaceutical, Dr. Reddy's Laboratories, Apotex, Glenmark Generics Ltd. and Lannett Co. Inc., the sources said.

Big players in the multibillion-dollar generic drug industry stand accused of conspiring to boost prices in a marketplace in which consumers assume they are buying lower-priced versions of widely used drugs.

Two senior executives from drug companies alleged to have engaged in the illegal conduct are also being sued, the sources said.

Connecticut Attorney General George Jepsen is leading the coalition of states.

The new complaint will address the relationships between such parties as wholesalers, distributors, large pharmacies and supermarkets, the sources said, adding that it will also cover the agreements with manufacturers to keep prices high.

The previous lawsuit, filed in December, had focused on Mylan N.V., Teva Pharmaceutical Industries Ltd. and four other companies. It had centered on just two medicines: a delayed-release version of a common antibiotic, doxycycline hyclate; and glyburide, an older drug used to treat diabetes.

The amended complaint expands the number of drugs to include glipizide-metformin and glyburide-metformin, which are among the most commonly used diabetes treatments, the sources said.

Others include: acetazolamide, which is used to treat glaucoma and epilepsy; the antibiotic doxycycline monohydrate; and the blood pressure medicine fosinopril. Others are the anxiety medicine meprobamate and the calcium channel blocking agent nimodipine, the sources said.