Aventis

(AVE)

is doing all it can to build market share for its allergy drug Allegra -- including improperly marketing it as unconditionally safe for pilots and air-traffic controllers, the government claims.

The

Food and Drug Administration

recently told the Franco-German drug maker to stop claiming that the drug has unqualified support from the

Federal Aviation Administration

for aviation personnel, where alertness is obviously paramount.

According to the FDA, Aventis marketing materials claim Allegra is "well suited for patients who need to stay alert," including military aviators. Such a claim is "misleading," the FDA said in a letter dated June 14 and released in the past week. The FDA sends a half dozen or so such letters each month to drug companies.

"This unqualified promotional presentation could have safety implications," the FDA wrote. The FAA authorizes aviation personnel to use drugs only after individual review, it said.

Lisa Kennedy, an Aventis spokeswoman, said the company is "working with the FDA to clarify the language in promotional pieces."

The warning letter comes as Aventis and

Schering-Plough

(SGP)

fight a pitched battle for market share for their allergy drugs, which they say don't cause drowsiness like some older allergy drugs. Schering-Plough's Claritin dominates the market, with 1999 sales of $2.7 billion. Allegra generated $693 million in 1999 sales, a sharp 67% gain from 1998 levels.

Aventis shares closed up 3/16 at 73 3/8. Schering-Plough rose 15/16 to 51 3/8.