ARANYAPRATHET, Thailand (AP) _ A non-communist Cambodian resistance group on Tuesday welcomed the replacement of Khmer Rouge leader Pol Pot, saying it could open the way for talks with Vietnam on resolving the Cambodian conflict.

The radio station of the Khmer People's National Liberation Front said that Pol Pot's removal may lessen the disputes between the Khmer Rouge, who are radical communists, and the two non-communist factions of the Cambodian resistance.

The Liberation Front and the forces of Prince Norodom Sihanouk have long condemned Pol Pot, whose government was blamed for the massacres of some two million Cambodians while he was in power from 1975-78.

Khmer Rouge radio on Monday announced that Pol Pot had been replaced as military chief by Son Sen. It said Pol Pot had to retire under a new order signed by Khmer Rouge Premier Khieu Samphan setting 60 as the retirement age.

Vietnam has insisted that Pol Pot and other top Khmer Rouge leaders be ''eliminated'' before any talks can begin. Vietnam invaded Cambodia in late 1978 and toppled the Pol Pot regime in January 1979.

It then installed a pro-Vietnamese government headed by Heng Samrin, and has kept thousands of Vietnamese soldiers in Cambodia to battle the rebels.

The Reagan administration on Tuesday welcomed as ''a positive development'' the reports that Pol Pot had decided to retire, although U.S. officials said they were unable to confirm them.

His departure could clear a major obstacle to an agreement to provide for the withdrawal of Vietnamese troops from Cambodia, the State Department said.

''Pol Pot can, obviously, have no future in Cambodia,'' said department spokesman Charles Redman.

The Reagan administration, which does not recognize the Heng Samrin government, is supporting diplomatic efforts by the Association of Southeast Asian Nations (ASEAN) for the withdrawal of the Vietnamese from Cambodia. At the same time, the United States is assisting the two non-Communist guerrilla forces.

The replacement of Pol Pot has also been welcomed by non-communist nations of Southeast Asia. These nations oppose the Vietnamese occupation but also do not want the Khmer Rouge to return to power.

Malaysia's deputy prime minister, Musa Hitam, said the retirement of Pol Pot might lead to more foreign aid to the resistance.

A senior Thai army officer reported that Khmer Rouge guerrillas attacked Cambodian government forces near the Thai border, killing seven soldiers and wounding more than 10 others Saturday.

The officer of the Eastern Field Force said the guerrillas divided into small groups and attacked the government forces opposite the area south of the key Thai border town of Aranyaprathet, about 135 miles east of Bangkok.

One Khmer Rouge guerrilla was killed in the 20-minute exchange, said the officer, who spoke on condition of anonymity.