The prosecution in the trial of Oliver North says it has added to its witness list the names of a former congressman whom North is accused of misleading over aid to the Contras and of beer magnate Joseph Coors, who says he gave the Nicaraguan rebels $65,000 after meeting with North.

Also on the revised list of prosecution witnesses against the fired National Security Council aide is William Langton, president of Southern Air Transport, a former CIA proprietary involved in both the Contra resupply operation and the administration's secret arms sales to Iran.The new names were on a list that actually contains fewer names, 40 rather than 87, reflecting a motion by independent counsel Lawrence Walsh to dismiss the two central charges of conspiracy and theft against North.

But at a hearing Monday, U.S. District Judge Gerhard Gesell said he wouldn't dismiss the charges until Attorney General Dick Thornburgh explains the administration's refusal to declassify information Gesell says must be released for North to get a fair trial.

An interagency group in the Reagan administration has declined to declassify certain material in 300 prosecution exhibits Walsh wants to present at trial, which forced Walsh to seek dismissal of the two central charges. Twelve charges remain.

Walsh said he is "quite sure" he can get an affidavit from Thornburgh.

Justice Department spokesman Loye Miller declined to comment on whether Thornburgh would supply an affidavit, but a department source said he assumed the attorney general probably will submit one.

Former U.S. Rep. Michael Barnes, newly on the prosecution witness list, in mid-1985 asked the NSC whether the staff was assisting the Contras and requested all information pertaining to contact between North and rebel leaders.

The response to Barnes said that "none of us has solicited funds, facilitated contacts for prospective potential donors, or otherwise organized or coordinated the military or paramilitary efforts of the resistance."

Coors made the $65,000 contribution to the Contras after meeting with North in 1985, less than three months before the letter to Barnes from the NSC.

Coors has said he met in June 1985 with then-CIA Director William Casey, who referred Coors to North when Coors expressed an interest in giving money to the Contras at a time when U.S. military aid to them was banned by Congress.