The British Columbia Supreme Court reduced by $300,000 the fine the Vancouver Canucks were assessed by National Hockey League President John Ziegler because of the signing of General Manager Pat Quinn.

On Jan. 9, the Canucks were fined $310,000 and Quinn was suspended from coaching in the NHL until 1990. Quinn signed a future-services contract with Vancouver after his contract to coach the Los Angeles Kings expired.

Justice Patrick Dohm said the Canucks and Quinn acted in a forthright manner and that there was nothing wrong with keeping confidential the agreement between the Canucks and Quinn.

Dohm said Ziegler exceeded his jurisdiction in fining the team $310,000 and he reduced the fine to $10,000.

Dohm said, however, that Quinn's suspension from coaching in the NHL until 1990 would stand . . .

A judge in San Diego ruled that British Olympic runner David Jenkins will stand trial in March on U.S. government charges that he masterminded a $70 million-a-year black market in anabolic steroids.

Jenkins' attorney, Robert Grimes, and U.S. Attorney Philip Halpern had been discussing a plea bargain for Jenkins, Justice Department sources said, but Halpern is busy with another trial and any chance of an early deal fell through.