LIBERALS ARE mildly surprised to find that corporate America is on their side on the question of diplomatic recognition for "Marxist" Angola and the repeal of the Clark Amendment. Big business is being guided, as always, by the profit motive.

The conduct of the multinationals in Angola is in striking contrast to ITT's performance in Chile. Faced with the onset of the leftist regime of Salvador Allende, ITT plotted with the CIA to destabilize the political situation, and helped usher in the infamous Pinochet regime.

In Angola, U.S. interests are working to block the repeal of the Clark Amendment, which specifically forbids overt or covert CIA activity in the civil war there. Sen. Nancy Kassebaum of Kansas is the author of the repeal movement, which won in the Senate but has less chance in the House. Her contention that it is "bad law" finds no response among the many firms which are collaborating with the Soviet-trained President Eduardo dos Santos in his efforts to develop Angola's rich resources, which include diamonds, oil, gold and strategic minerals.

Rep. Howard Wolpe (D-Mich.), the MIT graduate and onetime Peace Corps consultant who heads the House African subcommittee, recently went before a dinner meeting at the Carnegie Endowment to report on a recent African tour.

Citibank, Gulf, the Equator Bank were on the nametags. When Wolpe said he had never met "more capitalist Marxists" than Angolan officials, there was much vigorous nodding.

By way of illustration, he pointed out that the Angolan government has retained the consulting firm of Arthur D. Little of Boston.

"We get so hung up on labels," Wolpe declared, "that we fail to understand the political realities in Africa."

Actually, he said, there is not that much difference between the ideologies of dos Santos and Jonas Savimbi, the UNITA rebel leader, whose anticommunist statements have won him favor at the White House.

"They are are both ambitious nationalists, struggling for power," Wolpe said.

The Reagan administration seems to be suggesting -- through its push for Clark repeal and its cosseting of Savimbi's South African allies -- that Savimbi, who as Wolpe noted, has made speeches against "American imperialism," would suit us better. The unhung-up business executives, however, think that Savimbi is an ultra-black, who, despite the support of ultra-conservatives like Jesse Helms, would be far likelier to nationalize and expropriate western interests.

The business community was shocked last winter at rumors that Savimbi would be invited to the White House, and under its patronage be born again as a Freedom Fighter. Gulf Oil's President for Exploration and Production, Melvin Hill, came to Washington to relay corporate America's alarm and dismay at the prospect. He spoke at length with Vice President Bush on the subject.

The stumbling block for recognition for Reagan, as it was for Carter, is the presence of some 18,000 Cuban troops. Wolpe told his audience, and no one disagreed with him, that the dos Santos government would like to expel them but does not dare as long as the question of Namibia -- and the threat of South African invasion -- remains open. Reagan's refusal to condemn South Africa's recent aggression sent new fears through Angolan officialdom.

Do not expect to find certain sympathy for the beleaguered white rulers of South Africa in executive suites. American trade with black African countries far exceeds trade with South Africa, and American businessmen are as pragmatic as the authorities in Angola.

Angola has a friend at Chase Manhattan. Its officer in charge of Africa, Brian Henderson, wrote in a scholarly weekly recently that the presence of the likes of General Tire and IBM has "effectively limited Soviet influence and strengthened the government's commitment to nonalignment."

In its latest newsletter, Gulf Oil, which this year signed a $160 million deal for a joint venture with Sonangal, the Angolan national oil trust, assured stockholders that the government of Angola is "reliable, cooperative, businesslike and very market-oriented."

The State Department has sanctioned this cordial state of affairs between the multinationals and Angola. And the administration has not blocked the loans floated to the government by the Export-Import Bank.

The banks have to be circumspect about their dissidence on the Clark Amendment and on recognition -- "It's so easy for them to get back at us," one of them sighed. But Gulf is up front about its position and will testify on Capitol Hill.

The administration, curiously, has yet to see that good business is good foreign policy. "They want to turn back the clock," said a Wall Street banker disapprovingly.