The owners of Maryland's four thoroughbred race tracks reportedly have agreed to 1979 dates, with major variations from past years. Meanwhile, the Washington area's two harnessracing tracks apparently are set to fight over dates for the first time.

Under the thoroughbred plan, Laurel Race Course will open the 1979 season as a extension of its 1978 dates and Bowie Race Course will have three separate meets - in winter, summer and fall.

Such an allocation of dates, which would keep Pimlico (76 days) and Timonium (42 days) racing on approximately the same dates as in the past, still needs a few loose ends tied, industry sources said. The managment proposal is expected to be presented to the Thoroughbred Racing Board by Monday.

The arrangement would appease Ben Cartin, chairman of the Maryland House Ways and Means Committee. He vehemently opposed the 48-day summer meetings in which the three mile tracks pooled dates and ran them at Pimlico and Bowie. That arrangement drew strong opposition from neighborhood groups, especially in Cartin's home base of Baltimore.

Here is the lineup, although the exact number of dates is not set: Laurel, followed by Bowie, Pimlico, Bowie, Timonium, Bowie and Laurel. Bowie has 112 dates, including 36 it purchased from Marlboro Race Track.

For the first time, Laurel Raceway management is seeking the spring dates usually raced at Rosecroft. With an additional 18 days granted by the legislature this year, each track has 85 racing dates.

Earl Palmer Brown, Rosecroft president, has asked for an 85-night meeting, starting March 22 and ending June 30. He said, "I'm opposed to split meets. I don't know if there will be a fight. If we can't agree, the commission has to make a decision. We've had those dates for 25 years."

Joe Shamy, Laurel Raceway administrator, submitted three date requests, In order of preference to him, they were March 15-June 23; March 1-June 9, and a split meet of 45 days March 1-May 11, followed by 40 nights June 28 to Aug. 11.

"To have them open a week early and run until July is bull," said Shamy: "That would saddle us with the dog days of August and the football season. They must think we're a bunch of idiots."

Shamy said he was getting bids to remodel and enclose part of his the Laurel grandstand to make the track suitable for winter racing.

Shamy also said that he and the track's majority owners, who control 50 per cent of the stock, will seek to buy out minority stockholders who have 51,000 shares. Shamy said he is offering $15 per share cash or $20 per share term and that the reason for buying out the minority stockholders involves tax advantages.