The Associated Press

NEW YORK - Major league baseball has banned THG, the recently unmasked steroid at the center of the case against the Bay Area Laboratory Co-Operative.

The health policy advisory committee of management and the players' association unanimously determined last Thursday that THG builds muscle mass and should be added to baseball's list of banned substances.

"Testing for THG is an important step toward reaching our goal of zero tolerance," baseball commissioner Bud Selig said. "I am committed to that goal and advocate a more stringent and effective drug-testing program in the major leagues, similar to our program in the minor leagues."

The Food and Drug Administration ruled Oct. 28 that THG, or tetrahydrogestrinone, is an illegal drug that lacks federal permission for sale in the United States.

Because baseball and other sports did not know about THG before last October, drug testing was unable to detect it.

Barry Bonds' personal trainer, Greg Anderson, was among four men indicted last month on charges of illegally supplying performance-enhancing drugs from BALCO. All four pleaded innocent.

Bonds, Jason Giambi and Gary Sheffield, among the athletes called to testify before a grand jury, have denied using illegal steroids.

Selig told a Congressional committee last week that he hopes to have a tougher testing plan than the one called for in baseball's labor contract.

Players with major league contracts are tested only twice in a one-week period each year, and penalties - no suspension until the second offense - are far weaker than for Olympic sports.

The day before the hearing, Selig sent a letter to the union asking to discuss the drug agreement. The players' association has not yet responded.

"There are modifications you think about as circumstances change and as the law changes," union head Donald Fehr said after meeting with the New York Yankees in Tampa, Fla. "We'll have to see how it goes. Obviously, nobody is interested in condoning any illegal substance."

Selig is powerless to act unilaterally because drug testing is covered by collective bargaining.