Arthur S. Lowell, a New Jersey attorney who has been the subject of an intensive federal investigation into corruption at the General Services Administration, was convicted Thursday of conspiring to bribe two GSA inspectors assigned to check the quality of paint supplied to the GSA by one of Lowell's clients.

Testimony at the trial in U.S. District Court in Newark, N.J., alleged that Lowell paid the two GSA employees $250 and $100 a month, respectively.

The payments were made, according to testimony, as "insurance" so that the inspectors would approve paint supplied by Atlas Paint & Varnish Co. of New Jersey and the company would continue to receive GSA contracts.

Lowell, who lives in Tenafly, N.J., has represented Art Metal-USA Inc., which has been the largest supplier of metal office furniture to GSA for years. The firm has continued to sell$25 million worth of equipment a year to GSA, despite complaints from federal agencies that tops of desks fall off, finishes peel and corrode, and drawers and locks in file cabinets don't work.

Lowell also represented Dr. Laszio N. Tauber a Bethesda surgeon and real estate entrepreneur, when Tauber leased to GSA a nine-story Washington office building that remained largely vacant for two years because federal agencies refused to move to its remote location at Buzzard's Point.

Lowell's role in representing these and other clients, and his relationship with former GSA Administrator Arthur F. Sampson, have been under intensive investigation by the Justice Department's task force on GSA corruption headed by William S. Lynch. It was Lynch's group that brought the indictment that resulted in yesterday's conviction of Lowell.

In an interview in The Washington Post last year, Lowell suggested that complaints about Art Metal were prompted by GSA employees who resented his close association with various GSA administrators, particularly Sampson.

In a subsequent appearance before the Senate Government Affairs' federal spending practices subcommittee, Lowell invoked his Fifth Amendment rights against self-incrimination when asked if he paid off GSA inspectors to approve Art Metal furniture.

One of the two GSA paint inspectors, Anthony Pionzio, was also convicted yesterday on charges of bribery.

Joseph Montalbano, who headed the GSA laboratory in New York that approved the paint had previously pleaded guilty to bribery charges.

Lowell, 62, is charged separately with trying to obstruct a criminal investigation.

The indictment alleges that Lowell advised Atlas in 1977 that it should continue to make payoffs after investigations of GSA scandals has begun, but warned that care was required because Pionzio was under investigation. A seperate trial will be held on those allegations.

So far, more than 70 persons have been convicted in the GSA scandals.