Treasury Secretary James A. Baker III yesterday said his recent talks with South Korea's new president, Roh Tae Woo, have convinced him that South Korea will seek to resolve three key economic disputes with the United States -- restrictions on imports of cigarettes and high-quality beef, and greater protection for U.S. intellectual property rights.

Baker said that following inaugural ceremonies for the new president last week, he pressed South Korean officials for action in these areas, and for an increase in the value of the South Korean won compared to the dollar, to reflect the growing strength of the South Korean economy.

"We made the point that Korea is an unqualified success story, that it had emerged from the ranks of lesser developed countries, and that it had become a real player on the international economic scene," Baker said in an interview.

Baker also revealed that his talks had all but settled the question of access by American life insurance companies to the South Korean market. U.S. officials had been on the verge of taking an action against Seoul on this touchy issue under Section 301 of the trade act.

In 1987, South Korea had a trade surplus of about $10 billion with the United States -- a stunning change from 1985, when it had a deficit of about $1 billion. The 1987 surplus is roughly equal to 8 percent of its gross national product, which in relative terms is about twice as large as those of either Japan or West Germany.

The South Korean surplus and the nation's economic policies also have become issues in the U.S. presidential campaign, with some candidates citing South Korea's "unfair" trade practices as an example of the need for protectionist legislation.

Baker said he had told Roh that existing economic problems between the United States and South Korea would have no effect on the U.S. commitment to South Korea from a security standpoint, which is "firm, absolute and unswerving."

In the interview, Baker said that even though the United States has been pressing South Korea to open up its markets and revalue its currency, "I don't think the Koreans doubt the commitment of the United States on the security side. But we thought that it was important that that be restated, and it was."

In talks with Roh, Finance Minister Sakong Il and other officials, Baker cited U.S. objections to South Korea's restrictions on imports of beef and cigarettes and complained that it -- like other newly industrialized Asian countries -- does not adequately protect American intellectual property rights, such as patents and copyrights.

Baker said that no specific agreements were reached on cigarettes, beef or intellectual property, "but I had the feeling that this is a new government {that feels it} needs to move in a meaningful way to resolve these little rough spots in the economic relationship. And I think there is a genuine desire there to do that, working cooperatively with us."

Baker added that the South Koreans seem willing to cooperate with the Reagan administration's efforts to block protectionist legislation.

"It's our position that Korea is now a major trading nation, enjoying the benefits of a system of free and open trade, and as such, has responsibilities to that system. The Koreans readily agree, and they share our view that whatever rough spots there are in the economic relationship can best be resolved by the kind of consultation and discussions and negotiations which we have been engaged in," Baker said.

The administration complains that the huge South Korean trade surplus has been generated at least in part by import restrictions, along with the government's refusal to let its currency appreciate sufficiently in view of "the strengthening" of the South Korean economy. The dollar has declined less than 15 percent against the won since 1985, compared with 50 percent against the Japanese yen. That has given the South Koreans an advantage in the American market against competing Japanese goods.

The South Koreans resist a further rise in the won. They argued with Baker that new wage increases about to come into effect will raise production costs in their country, thus boosting the real exchange rates. The American counterargument is that relative to the dollar, there could be a further substantial appreciation of the won in nominal terms.

The details of the agreement on insurance will be announced shortly, according to Treasury officials. It provides that American life insurance companies can enter into joint ventures as majority partners with the insurance entities of South Korean conglomerates called chaebols, ranked 16 through 30 in size. They can join as minority or majority partners in chaebols ranked 31 through 50.