Stephen H. Sachs, Maryland attorney general, said yesterday that legislation to reduce the amusement tax on the Washington Capitals apparently would be constitutional.

Sachs said reduction of the tax from 10 percent to one half of 1 percent on the team's gross receipts for three years, as requested by team owner Abe Pollin, is not in violation of the 14th Amendment's equal-protection clause.

The constitutionality of a bill to give the Capitals a tax break, while maintaining the original tax on other events at Capital Centre, had been questioned by Charles S. Blumenthal, Prince George's County delegate.

Pollin listed the tax decrease as one stipulation for the team's continued operation in Washington, the others being sellouts of the first 10 home games, the sale of 7,500 season tickets and reduction of rent on the arena, all to be satisfied by Aug. 20.

If those conditions are met, at least four investors will purchase 50 percent of the team from Pollin.

The rent drop has been approved by the Equitable Life Assurance Society, which holds the bond on the building. The Prince George's County Council is expected to approve the tax cut at an Aug. 24 meeting.

Sachs, writing an eight-page opinion, said, "Given the broad discretion usually afforded legislative bodies (regarding taxes), we believe such a tax would most likely be upheld as constitutional."

Although no legal cases in the area have addressed this issue specifically, according to Sachs, cases from other jurisdictions have shown latitude extended by courts to legislators "in making classifications for tax purposes."

To date, the Capitals have sold 4,987 season tickets and area companies have guaranteed sellouts of nine games.

Yesterday, WTOP radio announced it would sponsor the team's Nov. 7 Hartford game.