Democratic congressional candidate Michael Barnes yesterday accused his opponent, Rep. Newton I. Steers (R-Md.), of owning $150,000 worth of stock in firms that could benefit from Steers' membership on two House committees.

Steers immediately responded to Barnes' charges of conflicts of interest by saying he had abstained from voting on questions that might have affected two of the firms that Barnes "misunderstood the nature" of the third company.

In a press conference on the steps of the Rockville Mall. Barnes said Steers' ownership of "more than $100.000 worth of oil and gas stock" while he was "casting key votes" as a member of the ad hoc House Energy Committee was "unacceptable behavior."

Another "conflict of interest," according to Barnes, is Steers' holding of "more than $50,000 in savings and loan securities while serving on the House Banking and Currency Committee."

Informed of Barnes' statements, Steers said he has abstainted from voting the only three times that legistration affecting savings, and loan associations came up since he began serving in Congress in January 1977.

Concerning his ownership of oil stock. Steers said, "I had an opportunity to vote twice on deregulation of gas, and both times I voted against it.

The companies named by Barnes were listed in a net worth statement Steers published in the Congressional Record on Jan. 19. The firms, and the shares held by Steers and market value as of last Dec. 31, were: Wiser Oil Co. of Sisterville. W. Va., 800 shares, $47,200: WD-40 Co. of San Diego, 2,000 shares, $65,500: and Government Services Savings and Loan Inc., of Bethesda, 6,000 shares, $44,250.

Steers said he voted against an amendment proposed by Rep. Clarence Brown (R-Ohio) in both committee and on the House floor that would have removed a ceiling on the price of gas and oil.

"I did vote for the final bill, which the Democrats pushed for like hell and which the Republicans wanted me to oppose, that continued regulation, at a price of $1.70 something instead of at the old price of $1.40 something," Steers said.

Barnes, at his press conference, said Wiser Oil "is a gas and oil producer which also owns a public utility." Steers' "vote for new gas and oil would have a rather beneficial effect" on such stock ownership, Barnes charged.

Steers emphasized that he has never voted for deregulation. He stated in a newsletter carlier this year that he favored deregulation on new oil and gas, but that has not come to a vote.

John C. Wright, president of Wiser, said in a telephone interview yesterday that the company has 200 employes, and produces and explores for gas and oil and owns a small retail gas company. Peoples Gas Co. of Kentucky. There are 15 million shares of Wiser, most recently traded over the counter at $62.66, Wright said.

Steers said he has "lost money" on his investment in Government Services, the savings and loan association. "It cost me $88.778.97, and its market value last Wednesday was $71,250," Steers said.

The freshman congressman said he abstained twice from votes on the banking committee "to foreclose the tiniest criticism, which he (Barnes) is now raising." The legislation, the Financial Institutions Regulatory Act (FIRA) passed in committee by a vote of 41 to 0 but has not yet come to the floor of the House for action.

Last Nov. 3, Steers abstained from voting on the floor on what he said was the only legislation affecting sayings and loan institutions. According to the Congressional Record of the next day, Steers explained in a floor speech that he voted "present (neither yes or no) . . . to avoid even the appearance of voting in favor of legislation that might help my stock." The legislation, which affects interest rates, passed the House by a vote of 395 to 3.

Steers said Barnes was "completely erroneous" in suggesting that WD-40 Co. which Barnes described as an oil company would benefit from higher gas and oil prices. "It doesn't sell oil, it buys oil," Steers said.

John Barry, president of WD-40, confirmed in a telephoned interview that is firm is "a one-product company" that sells WD-40, "a spray can lubricant that fixes everything that squeaks, sticks or rusts." Barry said WD-40 uses "petroleum and chemical products as source of ingredients." As for deregulating the price of petroleum products, "we don't want that," he said.

Barry added that he had never heard of Steers. The company has 31 employes and had sales of $20 million last year. There are about 1.2 million shares of WD-40 stock, which currently is being traded at $51.53, a share, Barry said.

Informed of the company president's remarks. Barnes said he based his information "on filings with the SEC (Securities and Exchange Commission) that indicated WD-40 manufactured a petroleum product."

Given the correct information, Barnes said Steers ownership of WD-40 stock "is not anywhere in the same class with Wiser. I might exclude it" from charges that Steers should have sold it or placed it in a blind trust."