Yankee Doodle went to London yesterday, in the person of John D. Schapiro, just to see the ponies - and to promise the world the annual Washington, D.C. International at his Maryland thoroughbred track. Laurel Race Course, is going to grow bigger and better.

Call it the final leg of the "International Triple Crown," Laurel president Schapiro said of the 1 1/2-mile grass race that annually tops off the area turf year but seemed to lose a bit of luster in recent runnings.And take note, he declared, that prize money - $150,000-added in 1976 - will be boosted to $200,000 for the 26th running Nov. 5. That, he hopes, is just the start: Laurel is pursing sponsors with a view to working the purse up to $500,000.

The first two legs of the international triple, if it indeed gains such recognition, are the King George VI and Queen Elizabeth Diamond Stakes at Ascot and the Prix de I'Arc de Triomphe at Longchamp in October The George and Elizabeth comes up Saturday: hence Schapiro's presence to look over potential D.C. International invitees . . .

Too bad old "Jaws" - the exciting Irish-trained 3-year-old Marinsky - won't be on view because of his ban from English tracks for biting rival horses and jockeys en route to the wire . . .

Reports are popping up all around the hockey belt that the NHL-WHA merger is in big trouble. A spokesman for the senior league terms reports of the plan's collapse "premature," but one gent who's not waiting around to find out is Ron Grahame, goalie: WHA-leading goalie last year for Houston, 2.74 yield per game: WHA-leading goalie and playoff MVP, 1974-75. And now Grahame has signed a 1977-73 contract with the NHL's Boston Bruins: a little help for thoroughbred-owning goalie Gerry Cheevers. Grahame played out his option with the Aeros and Houston coach Bill Dineen said he is sure the NHL merger committee's indecision hastened the player's decision after he'd spent two weeks comparing Houston and Boston offers . . .

A feud in the NBA: Bob Bass, San Antonio Spurs assistant coach, vs. Simon Gourdine, deputy commissioner. Owner and general manager on the basketball circuit recommended Bass as NBA supervisor of officials, a position he held in the late ABA three years ago. Bass told reporters that when he telephoned this week to inquire about the job. "Gourdine asked me to come to New York for an interview, but refused to pay my expenses. Throughout all of this Gourdine is cold and clinical . . . It is an out-and-out insult to ask me to pay my own expenses in a situation like this. 'It's as though he's telling me. 'Get in your place, boy. (Gourdine is black, Bass white.) When I told him that over the phone he wanted me to retract my statement. I didn't retract anything. In fact, I told him something else" . . .

In the insult league, New York Yankee owner George Steinbrenner ranks that Bronx-cheerer, 13, who vawped to police that Reggie Jackson chased and stomped him (Jackson denies the latter) after the All-Star Game, up there with the worst of 'em. Steinbrener came to Jackson's defense yesterday with "the facts," namely that Reggie had spent 15 minutes giving autographs to youngsters who breached a security area in the first place and that he grew angry only when several of the youths "started to shout obscenities that were so bad and so vile that you cannot print them." Jackson, and witnesses, said he put up with it until someone made a particularly vile remark about his mother . . .

Don King, again. Now the network-hopping promoter has lined up seven of the top-ranked 10 challengers to Muhammad Ali for the Sept. 14 NBC-TV live, prime-time heavyweight boxing show from Caesars Palace: Add Ron Lyle vs. unbeaten youngster Stanley Ward, and unbeaten Larry Holmes vs. Howard Smith, to Ken Norton-Lorenzo Zanon and Jimmy Young-Jodie Ballard for a quadruple-header in the three-hour slot . . .

Catholic University has a new head baseball coach, billed as a the youngest in the nation at a major school: the CU catcher last season. Tim McCormick, 22. He came out of Carroll High - a 1973 All-Met football guard - and played every baseball position but first base for the Cardinals, capping his career by batting .378 as CU made the 1977 NCAA regionals. McCormick, who also will work as an admissions counselor under his predecessor coach. Bob Talbot, already has named his assistant: teammate Mike Maher, another '77 graduate.