Major league baseball owners took less than 90 minutes yesterday in Chicago to ratify, by 12-5, the basic agreement hammered out last month to avoid a strike by players.

Ray Brebey, who represented the owneres in the negotiations, said the settlement was outlined to the 26 owners and there was little discussion of the terms.

He said teams voting against the proposal, which was initialed by representatives of the players association and the owners on the morning of May 23, were St. Louis, Oakland, Minnesota, Cleveland and San Diego.

St. Louis Cardinal President August Busch was apparently the most militant opponent among the owners, maintaining they should have stood firm on the key compensation issue for future free agents.

Gene Autry, owner of the California Angels, ahd circulated a letter urging the owners not to accept the proposal. But when it came time for the Angels to vote, Buzzie Bavasi, executive vice president, wound up voting for the proposal.

The players compensation issue was the major roadblock to both sides reaching agreement until just hours before the players' May 23 strike deadline.

Under the provision, a study committee made up of two players and two general managers will convene no later than Aug. 1 to review the current method of awarding compensation to teams that lose free agents.