PARIS (AP) _ France has offered to organize a meeting of the warring Cambodian factions followed by an international peace conference, the Foreign Ministry announced.

''To this end, it has decided to intensify its diplomatic activity with each of the countries involved'' to encourage their participation, the ministry said in a statement late Saturday.

France is ''at the disposal of the Cambodian parties to organize, in the form which appears appropriate to them, a meeting that might encourage a true national reconciliation and open the path toward the holding in 1989 of an international conference,'' it said.

It said the issue was discussed at a meeting Friday between resistance leader Prince Norodom Sihanouk and Foreign Minister Roland Dumas.

Sihanouk has met three times in France with Cambodian Prime Minister Hun Sen and also met in November with Khieu Samphan, a leader of the Communist Khmer Rouge.

Representatives of the four factions - Sihanouk's army; the Khmer Rouge; a smaller anti-Communist group called the Kampuchean People's National Liberation Front; and Hun Sen's Vietnamese-backed government - are scheduled to meet next month in Indonesia, as they did last July.

The three rebel groups are fighting the Communist government installed after the Vietnamese invasion of Cambodia 10 years ago ended the Khmer Rouge's reign of terror.

Thailand's foreign minister, Siddhi Savetsila, said Sunday in Brunei that the Soviet Union, the United States and China might be invited to join in Cambodian peace talks if their participation would be helpful.