Federal prosecutors in Baltimore will not open an investigation into claims by former Rep. Robert E. Bauman that aides to political opponent C.A. Porter Hopkins tried, in a poorly disguised "extortion" attempt, to force Bauman out of running for his old 1st District congressional seat.

U.S. Attorney J. Frederick Motz released a statement yesterday saying that members of his office met with Bauman and two of his aides on Aug. 2 to discuss the charges Bauman made against his former primary opponent. "We have concluded that it does not warrant our conducting an investigation or taking any further action," the statement said.

Bauman, who withdrew from the congressional race last week citing "virulent and scurrilous personal attacks" by Hopkins' top aides, could not be reached for comment yesterday. Several days ago, after his meeting with federal prosecutors, Bauman had claimed that Hopkins' finance chairman and campaign manager had offered to pay off Bauman's campaign debts if he would get out of the race. If he did not, they threatened to "reveal things," Bauman claimed.

Hopkins and his staff members have denied they attempted to coerce Bauman out of the race to unseat the current incumbent Democratic Rep. Roy Dyson.

A one-time powerful conservative in the House, Bauman lost his seat in 1980 after admitting he was an alcoholic who suffered from "homosexual tendencies."

Hopkins said yesterday he was not surprised by Motz's decision. "I never expected it to go any other way," he said.

He added he believes the hostility between the Bauman and Hopkins campaigns could leave the local Republican party divided.

In a related development, Sidney S. Campen Jr., the state prosecutor of Talbot County where Bauman lives, said he is looking into Bauman's allegations.