South Korea accepted a North Korean proposal today to follow up the unprecedented delivery of flood relief goods by discussing cooperation in sports.

But the South did not respond to other suggestions from the North, broadcast yesterday by its official Radio Pyongyang, that the two nations keep open a telephone hotline and discuss joint economic and cultural programs.

Seoul's announcement came this afternoon as North Korean ships unloaded the last of 100,000 tons of cement at two South Korean ports and prepared to sail home. Delivery of rice, cloth and medicine was completed last weekend.

The announcement raised hopes here that the aid transfer might mark the start of a dialogue that eventually could move on to substantive questions dividing the two governments, which remain intensely hostile three decades after the end of the Korean War.

In a message to the South Korean National Assembly this afternoon, President Chun Doo Hwan said his government would continue the contacts.

"We will do our best to hasten the reunification of the country by opening an era of dialogue, exchanges and cooperation with North Korea," he said.

North Korean President Kim Il Sung has expressed similar views to foreign visitors in recent weeks.

The South's response came in a letter from Roh Tae Woo, president of the South Korean Olympic Committee, to his counterpart in the North, Kim Yu Sen. Delivered this afternoon at the truce village of Panmunjom in the Demilitarized Zone that separates the two countries, it was also released in Seoul.

The tone of the letter was not conciliatory. Roh began by expressing regret that North Korea this summer broke off talks between the two sides toward forming a joint team for the Los Angeles Olympics or later international games.

At those meetings, held in Panmunjom, the South demanded that the North first apologize for a bomb blast last year in Rangoon, Burma, which killed 17 South Koreans, including four Cabinet ministers. Burma convicted two North Koreans for the crime.

The North responded that the South was injecting politics into a nonpolitical forum and that the South itself had perpetrated the bombing. The two sides met three times, until the North declined to attend a fourth sports meeting proposed by the South for Aug. 30.

In his letter today, Roh noted that the 1986 Asian Games and the 1988 Olympics will be held in Seoul. That point is a source of great pride for the South Korean government. Roh called on the two sides to field joint teams and to "begin right away to hold exchange matches and other sports exchanges."

There was no mention of Rangoon in Roh's letter, and South Korean officials made none in the talks that led up to the aid delivery.

Sports exchanges might take the form of each side sending a team to the other's capital or to an event in some third country, such as China. A soccer match in the Demilitarized Zone also has been suggested.

Roh called on the two sides to meet to discuss this "at an early date" with a "forward-looking and progressive attitude." He suggested no specific date, asking the North Koreans to do so.

In its broadcast yesterday, North Korea also proposed economic cooperation, in particular joint development. Similar proposals have been made before, but have never gone anywhere.

Most such proposals hinge on the fact that North Korea has most of the peninsula's natural resources, while South Korea is more advanced in manufacturing.

South Korea might jointly invest with North Korea in new coal or iron ore mines to supply its factories. For their output, payment might be in cash or in manufactured goods. North Korea recently passed a foreign investment law that would appear to make such ventures legal.

Cultural exchanges, also proposed by the North, might take the form of dance troupes or exchanges of art exhibits.

The North also suggested keeping open a telephone hotline between Seoul and the North's capital, Pyongyang. It was reopened to facilitate the aid exchange after being shut down in 1977 as an earlier round of talks died out.