A 7-year-old horse was killed Wednesday night on I-695 in Baltimore County when the trailer she was in broke loose from a truck and crashed. The mare, No Such, had won her first race in three years just hours before the mishap.

No Such was being shipped from Charles Town, where she had won the last race Wednesday, to her stable at Bel Air, Md., when the two-horse trailer became disengaged and tumbled near the Charles Street exit. According to a state police spokesman, no other vehicles were involved and no persons were injured. No Such, the only horse in the trailer, was found dead.

Clinton Bratton, the trainer of No Such, said the truck was driven by Joseph Yates, whose wife, Mary, was the mare's official owner. Bratton did not witness the accident but said the owners informed him by phone Wednesday evening.

No Such had won a $2,500 claiming race that afternoon -- her fifth victory in 47 starts -- and brought hope to her camp because it was her first race with Lasix, the medication for bleeders.

"There was a little light at the end of the tunnel," said Bratton. Competition for The Form

Publishing magnate Robert Maxwell announced yesterday he will start a daily racing newspaper in the spring to take on the Daily Racing Form. The Maxwell-owned Mirror Group has acquired the data base used by the now-defunct FIGS Form, whose personnel has compiled past-performance statistics for North American tracks over the past four years even though the newspaper has ceased publication.

Steven Crist, former New York Times racing writer, will be editor-in-chief of the national publication called the Racing Times. . . .

Jehan Malherbe, a 34-year-old South African, will call Laurel's races in December as a replacement for Milo Perrins.

Malherbe, a former show-jumping champion who has been announcing since 1979, is committed to calling races in South Africa this January and February, according to Laurel President Joe De Francis. De Francis said Malherbe might be given an option to return in March if he's willing to call races here year-round. Malherbe has announced one race in the United States, at the Meadowlands in 1988.

Perrins, who has worked the Maryland circuit since July 1989, is leaving Nov. 30 to call races in New Mexico. . . .

Referendums allowing parimutuel racetracks were passed Tuesday in the Virginia counties of Loudoun and Nelson, near Charlottesville. In New Jersey, voters approved Sunday racing and the simulcasting of races to Atlantic City casinos. . . .

Tigors won a $35,000 claiming race yesterday, but trainer John Lenzini was none too elated. Tigors, one of his two best 3-year-olds, was claimed by King Leatherbury from a race Lenzini said he hadn't sought. Tigors has all his allowance conditions remaining.