A former official of the Wedtech Corp. said in an affidavit made public yesterday that he believes Attorney General Edwin Meese III intervened with the Pentagon in support of the company's efforts to win $134 million in no-bid Navy contracts to build pontoons.

Mario Moreno, who was executive vice president of the Bronx-based defense contractor, told investigators Monday that he understood Meese, then counselor to President Reagan, had contacted Defense Secretary Caspar W. Weinberger about the matter around December 1983, when the Navy was still determined to ask for competitive bids on most of the work.

The Navy reversed its position in early January 1984 and turned over the entire program to the Small Business Administration, which immediately named Wedtech as its candidate.

The company was given its first $24 million no-bid pontoon contract on April 17, 1984.

Meese attorney James Rocap said that "Mr. Meese does not recall being involved in the pontoon contract at all." Defense Department spokesman Fred S. Hoffman said "Secretary Weinberger has no recollection of Mr. Meese interceding with him on behalf of Wedtech."

Meese is under investigation by independent counsel James C. McKay for his intercession on Wedtech's behalf in connection with a $32 million Army engine contract, but his name has not come up publicly before in connection with the Navy pontoon program.

Moreno, who pleaded guilty to bribery-conspiracy charges in the Wedtech scandal earlier this year, said his information came from Wedtech lawyer-consultant E. Bob Wallach, a close friend of Meese for many years.

Moreno, whose Sept. 28 affidavit was made public at a Senate hearing yesterday, said he had regular conversations with Wallach in the fall of 1983 and Wallach in turn "reported that he had spoken to 'his friend' and kept 'his friend' informed of Wedtech's efforts to obtain the Navy pontoon contract.

"In the context of prior conversations with Mr. Wallach, I took 'his friend' to mean Edwin Meese III, then counselor to the president," Moreno said.

Wallach could not be reached for comment, but his lawyer, Robert Kasanof of New York, said Wallach "did not ask Meese to intervene improperly with the secretary of defense."

Rocap said it was "wrong" to think Meese had talked to Weinberger. Rocap also said he thought it "outrageous that the committee would use an affidavit based on double hearsay and assumptions."

Moreno, who is now cooperating with authorities, testified that in December 1983, he learned that "only a very small portion" of the pontoon work was to be set aside for minority business and "I told Mr. Wallach that Wedtech would not accept" just the small slice.

According to Moreno, "Mr. Wallach told me that he would 'see what he could do.' " Shortly after that, Moreno said, Wallach told him he had spoken by phone to "his friend" and "later Mr. Wallach indicated to me that 'his friend' had communicated with Mr. Weinberger. I did not ask Mr. Wallach for any more details about this conversation."

Testifying at the Senate hearing yesterday, Assistant Secretary of the Navy Everett Pyatt said that he initially had been opposed to setting aside any of the pontoon causeway work for minority business because of its size and urgency. The 90-ton units were designed to get supplies in a hurry from huge pre-positioned cargo ships to U.S. rapid deployment forces dispatched to deal with a sudden crisis.

Pyatt said, however, that he decided on Dec. 8, 1983, at the urging of then-SBA Administrator James B. Sanders to set aside the simpler, nonmotorized pontoon work. Then on Jan. 6, 1984, he reversed himself again and informed Sanders that the Navy was "willing to entertain" placement of the entire program with the SBA.

The day the contract was signed with Wedtech on April 17, 1984, the White House announced that Pyatt's nomination as assistant secretary for shipbuilding and logistics, which had been stalled for months, would be sent to the Senate.

Sen. Carl Levin (D-Mich.) asked Pyatt yesterday about rumors that his appointment had been held up "because of your opposition to Wedtech." Pyatt said he never heard of them. He said the only pressure he felt was an obligation to meet the Navy's annual dollar volume quota for minority business work.

According to a Dec. 7, 1983, memo obtained from Wallach's files, Wallach said he had been "advised" that Pyatt's office "will issue a letter," written by Navy small business adviser Richard Ramirez, "which will set out qualifications that really apply only to Wedtech."

"Where did he {Wallach} get that from?" Levin asked.

"I haven't the least idea," Pyatt replied.

Levin said Wallach had told his investigators the report came from Washington lobbyist Mark Bragg, who is now awaiting trial with former White House aide Lyn Nofizger on conflict-of-interest charges stemming from lobbying for Wedtech on the Army engine contract.