Attorneys general from 29 U.S. states filed a lawsuit on Wednesday against Bristol-Myers Squibb Co, alleging the drug giant illegally kept cheaper, generic versions of its BuSpar anxiety medication off the market. 

New York state Attorney General Eliot Spitzer said in a complaint filed in federal court that Bristol-Myers violated state and federal antitrust laws by obtaining a new patent extending BuSpar's exclusive hold on the market. 

The complaint also alleged that the company knowingly made false statements to the U.S. Food and Drug Administration in an effort to prevent generic drug makers from selling their version of BuSpar and extend its ``patent monopoly,'' costing New York state consumers alone millions of dollars. 

The offices of the New York state and Texas attorneys general are leading a multi-state group of 29 states and Puerto Rico in the case. 

Mylan Laboratories Inc. and Watson Pharmaceuticals Inc. were cleared in late March to launch their generic versions of BuSpar after a four-month patent battle between Bristol-Myers and Mylan. But an appeals court in Washington ruled in October that the judge improperly gave the green light to Mylan.