Former White House political director Lyn Nofziger pleaded not guilty yesterday to six felony charges that he violated federal ethics laws by lobbying the Reagan administration on behalf of Wedtech Corp., Fairchild Industries and a marine engineers union.

After a brief appearance before U.S. District Court Judge Thomas A. Flannery, Nofziger and Mark Bragg, his partner in their public relations firm, who pleaded not guilty to a single count of aiding and abetting Nofziger, were released on personal recognizance. Trial was set for Nov. 16.

In a brief news conference on the courthouse steps after the hearing, Nofziger, wearing his customary rumpled sports jacket and Mickey Mouse tie, said, "I am absolutely convinced of my innocence.

"Frankly, this kind of thing just isn't something anybody would go out and deliberately do," Nofziger said. His lawyers have said he participated in the lobbying only after an attorney advised him it would not violate the ethcis law.

"I'm sorry to waste all the government's money on this kind of situation where they literally destroy a person's business . . . finances and his reputation," Nofziger said. The six-count indictment was unsealed last Friday.

Paul Perito, Nofziger's lawyer, said, "We will vigorously defend these charges. And we have no doubt at the end of the process that a jury of our peers will exonerate us."

The mandate of independent counsel James C. McKay, who brought the charges, was expanded May 11 to include an investigation of the role played by Attorney General Edwin Meese III in aiding Wedtech, the Bronx-based defense contractor at the center of five investigations.

Meese has acknowledged that he intervened in Wedtech's behalf in 1982 while counselor to the president after receiving about a dozen memos from E. Bob Wallach, a close friend who received more than $1 million from Wedtech and has become a central figure in the Wedtech investigations. At the time, Wedtech was seeking a $32 million, no-bid Army engine contract, which it obtained several months later.

McKay told reporters yesterday that the Meese inquiry is "going forward as expeditiously as possible. We hope to wrap it up in a reasonably short period of time. But it's hard to say how long it will take."

Nofziger, who left the White House on Jan. 22, 1982, is charged with violating the 1978 Ethics in Government Act. Under that law, it is illegal for a federal official to lobby his former agency within one year after leaving the government on any "particular matter" in which the agency "has a direct and substantial interest." There is also a lifetime ban on lobbying any part of the government on an issue in which the former official "personally and substantially" participated.

In early 1982 Nofziger set up a firm with Bragg, 42, a fellow Californian who spent many years in radio news and later became president of the Public Affairs Broadcasting Group, a California firm that produced documentaries.

The indictment charges that Nofziger, 62, began his lobbying on behalf of Wedtech in April 1982. Investigators have said that Nofziger and Bragg later received 45,000 shares of Wedtech stock that could have been worth well over $600,000, depending on when they were sold.

In addition to the Wedtech charges, Nofziger is accused of lobbying the White House in 1982 on behalf of Fairchild's A10 aircraft and for the National Marine Engineers Beneficial Association, an AFL-CIO-affiliated union that was seeking more civilian jobs on government-owned ships.