China is willing to continue its pragmatic cooperation with countries in South China Sea region and make it "a sea of friendship and cooperation," said China's Foreign Ministry Spokesman Liu Jianchao Tuesday.

"Oil companies from China, the Philippines and Vietnam signed a landmark agreement in Manila on Monday," Liu said at a regular press conference in Beijing,

adding that it is an important measure for the three parties to jointly implement the Declaration on the Conduct of Parties in the South China Sea, making historic contribution to the stability and peace in the region.

According to the agreement, a 15-million-US dollar joint marine seismic undertaking in the South China Sea will last for three years, a move that Philippine President Gloria Macapagal-Arroyo described as a "historic breakthrough", during her meeting with representatives of the three companies Monday afternoon.

In a joint statement, the three parties held that the agreement showed their willingness to explore the reserve of petroleum resources within the area agreed by them. But it would not undermine the basic positions held by the governments of the relevant countries in the South China Sea.

Liu said the cooperation efforts began last September when China and the Philippines signed a contract for conducting marine seismic undertaking.

"Vietnam signaled its strong interest in participation and finally joined the agreement through several rounds of negotiations," said Liu.