TIMONIUM, MD., OCT. 10 -- The Maryland Racing Commission took steps toward several rules changes today and approved 1991 racing dates for most of the state's tracks.

With all nine members present, the commission voted overwhelmingly to amend regulations governing certain fees to jockeys as well as the discretionary powers of the stewards. It also passed two proposed rules changes affecting coupled entries, and denied a request to change the weight allowances accorded apprentice jockeys.

The commission approved Rosecroft Raceway's 218-night schedule for 1991, in which the track would open Jan. 11, close for three weeks beginning Sept. 14, then proceed through Dec. 21. The track plans to operate four nights a week through February, five nights a week from March until its fall break. After returning Oct. 4, Rosecroft will not race on Sunday, largely to avoid competing with the Washington Redskins pro football team.

Rosecroft and Delmarva Downs, which was granted its customary 74 summer dates, would have the ability to revise their schedules next year given the fiscal uncertainties created by owner Mark Vogel. Vogel, a prominent real estate developer, is said to have diverted $2 million in track assets toward nonracing concerns; an examination of track finances by a public accounting firm should be completed soon.

Laurel and Pimlico race courses will apply for 1991 dates next month, which in turn caused the Prince George's Equestrian Center to defer its request for two specific dates. The equestrian center, formerly the site of Marlboro Race Track, usually runs on successive Wednesdays on which Laurel and Pimlico are closed.

Timonium Race Course received its customary 10 days during the Maryland State Fair, Aug. 24 through Sept. 2. Fair Hill, the steeplechase grounds, will race three days: May 27, Sept. 28 and Oct. 19.

In approving two rules amendments, which likely are to be invoked within four weeks, the commission will require a thoroughbred owner to pay only a losing jockey fee to any rider who is replaced on a horse after scratch time. The decision came despite protests from the Jockeys' Guild, which had recommended that owners pay the inactive riders the amount earned by their replacements. A winning jockey earns 10 percent of the horse's purse, considerably more than the $40 to $100 a losing mount generally brings.

The other amendment obligates the stewards to disqualify any horse who impedes another, regardless of whether they believe the contact affected the order of finish.

Two recommendations by commissioner Jack Mosner passed as proposed rules changes following a compromise of sorts with horsemen. They stipulate that different jockeys be named on a coupled entry no later than one hour before post time on the day of the race; the withdrawal of any part of the entry must be announced by then as well.

Mosner withdrew his proposal to split entries in overnight races, and agreed to table a petition to allow coupled entries in daily double races.

The commission denied a horsemen's request to change the rule that gives all apprentices a five-pound allowance regardless of experience.

The Maryland Thoroughbed Horsemen's Association sought to revert to the previous rule, which had granted 10- and 7-pound allowances to riders based on number of victories, saying the new system gives no advantage to the most inexperienced apprentices. But Jockeys' Guild representatives said drastic weight reduction often created by the 10-pound allowance necessitated the existing rule, and the commission concurred.