A company where Labor Secretary Raymond J. Donovan once worked, and two of its executives, have filed defamation suits over statements that prompted an investigation of alleged corruption at the firm.

The Schiavone Construction Co. of Secaucus, N.J., and Vice Presidents Joseph A. DiCarolis and Genaro Liguori filed the suits Tuesday in U.S. District Court. Each suit seeks $5 million.

Named as defendants were Mario Montuoro of New York City, former secretary-treasurer of Local 29 of the Laborers International Union, and five others listed as "John Does."

The complaints said that since December, 1981, Montuoro repeatedly and maliciously told reporters that DiCarolis paid a $2,000 cash bribe to Louis Sanzo, business agent for Local 29, at a meeting in a New York City restaurant attended by Liguori and company president Ronald A. Schiavone.

The company president filed an identical $5 million suit Sept. 2.

Montuoro could not immediately be reached for comment.

Donovan was a top executive of Schiavone during 1977, when the bribe allegedly was paid.

The allegations by Montuoro and others led to investigations by special federal prosecutor Leon Silverman to determine whether Donovan was involved in any corruption while he was with Schiavone.

Silverman said he concluded there was not enough credible evidence to link Donovan to organized crime