PHILADELPHIA (AP) _ SmithKline Beecham filed suit against two New York pharmaceutical companies Tuesday, accusing them of submitting false data to the government on generic versions of SmithKline's hypertension drug Dyazide.

Bolar Pharmaceutical Co. of Copiague, N.Y., and Vitarine Pharmaceuticals Inc. of Springfield Gardens, N.Y., manufactured and sold generic versions of Dyazide but pulled them off the market in the past year after allegations of false reports to the Food and Drug Administration surfaced.

The suit, filed in federal court, accuses Bolar of falsifying evidence that its generic drug achieves the same effect as Dyazide.

The suit accuses Bolar of back-dating testing studies to make it appear the company's tests were performed on a batch of Dyazide when in fact they were performed on a batch that was not prepared according to federal procedures.

Bolar took its version off the market in January because it appeared false documents had been used to support the company's claims for the product.

When it took its version off the market in June 1989, Vitarine admitted it substituted Dyazide for its product in tests required to win FDA approval.

''SmithKline was injured ... because those schemes and representations enabled (the companies) to obtain FDA approval ... to sell their generic versions of Dyazide to persons who otherwise would have bought Dyazide from (SmithKline),'' the suit claims.

Dyazide is one of SmithKline's best-selling products, with annual sales exceeding $300 million in 1987, according to the suit.

The suit characterizes the companies actions as a violation of the Racketeer Influenced and Corrupt Organizations Act and asks for unspecified damages.

Also named in the 12-count suit are Robert Shulman, who resigned as Bolar's president in February, and Port Washington, N.Y.-based Schein Pharmaceutical, Inc., the company that developed, marketed and sold Bolar's generic drug.

An assistant to Bolar's general counsel, who did not give her name, said she could not comment on the suit because the company had not received a copy of the complaint.

Officials at Vitarine did not return a message left at their offices.