OKLAHOMA CITY -- Six wholesale distributors of pseudoephedrine -- a key ingredient in methamphetamine -- were named Wednesday in a civil lawsuit filed by the state.

One of the wholesalers, Thinh Quoc Kieu, also was hit with a three-count federal indictment.

Kieu was accused of two methamphetamine-related offenses and of selling phony tobacco tax stamps, said U.S. Attorney Robert McCampbell.

McCampbell said Oklahoma County ranks No. 1 in the nation in the number of meth labs and the state as a whole is in the top four in per capita meth use.

The six wholesalers named in the lawsuit filed by Attorney General Drew Edmondson operate in the Oklahoma City area and are among 35 pseudoephedrine wholesalers registered statewide with the Drug Enforcement Agency.

Pseudoephedrine is legally sold as an ingredient in over-the-counter cold medications.

The idea for the lawsuit developed after the Oklahoma Bureau of Narcotics and Dangerous Drugs Control took evidence against the companies to the attorney general.

Malcolm J. Atwood, director of the state drug enforcement agency, said about 4,100 methamphetamine labs were seized statewide in Oklahoma from 1996 through June 2002.

The lawsuit accuses the wholesalers of civil conspiracy, negligence and creating a public nuisance by selling large amounts of pseudoephedrine that ended up in illegal labs.

It also allows violations of the Oklahoma Corrupt Organizations Prevention Act, the state's equivalent to the federal RICO Act.

In addition to Kieu, the suit named Moore Services Inc. of Midwest City, and Beck Services, Sun Distributing, Stevens Wholesale and Anna Wholesale, all of Oklahoma City.

"This is the first state action of its kind in Oklahoma and perhaps the nation," Edmondson said.