Hong Kong/Beijing: The Chinese government opposes a plan by Exxon Mobil Corp., the world's biggest oil company, to explore for petroleum in the South China Sea with Vietnam, saying the project marks a breach of its historical claim to the area.

"China opposes any activities that violate its sovereignty and jurisdiction over the South China Sea," Liu Jianchao, spokesman for the foreign ministry, said.

The South China Morning Post reported on July 20 that Chinese diplomats over the past months had repeatedly asked Exxon executives to pull out of the preliminary exploration agreement with Vietnam, citing people close to the company it didn't identify.

They said Exxon could put its future business interests in China at risk by persisting with the project.

"China's position on the South China Sea is clear and consistent," Liu said in the briefing in Beijing. "On this specific case, we have made our position clear to the relevant parties."

Evaluation

Exxon made public the agreement with the government in Hanoi last month, with joint technical and commercial evaluations already under way off Vietnam's central and southern coasts, the newspaper said yesterday.

Le Dung, spokesman for the Vietnamese foreign ministry, said Chinese companies are welcome to join other foreign investors in oil projects in the country, according to the Post.

In April last year, China said Vietnam's "new actions" in the Spratly Islands violated its sovereignty, after the Southeast Asian country announced a deal with BP Plc.