King Leatherbury, Laurel's leading trainer and perennial champion of the Maryland racing circuit, was suspended yesterday because one of his horses failed a postrace drug test.

The stewards issued Leatherbury a 15-day sanction, which begins Monday, after a blood sample from Wait For The Lady was found to contain an excessive amount of phenylbutazone, a widely used anti-inflammatory medication. The test followed a first-place finish by Wait For The Lady in the fourth race at Pimlico Sept. 15, her third straight victory. She was heavily favored.

The Maryland Racing Commission laboratory in College Park reported the level of phenylbutazone, or Bute, at 6.7 micrograms per milliliter of blood plasma; Maryland prohibits a level above 2.0. Leatherbury, 57, had a portion of the blood sample sent to a Delaware laboratory, which quantitated the level at 6.3 ug/ml.

The winning purse of $10,200 was redistributed.

Leatherbury could not be reached to comment yesterday. . . .

Most of the International Turf Festival horses from Europe -- about 15 of them -- are expected to arrive at Laurel late this afternoon. The group includes Timeless Times, a 2-year-old English colt who has won 16 of 20 starts this year; the recognized record for victories in a year, albeit North American, is 19 by Citation during his Triple Crown year of 1948. A Kentucky-bred, Timeless Times is heading for the $300,000 Laurel Futurity on Saturday.