BEIJING, Nov 17 (Reuters) - China offered to buy more goods from Brunei and to encourage investment in the Islamic sultanate as President Xi Jinping lauded relations with the tiny nation that have centred more on economics than territorial disputes in the South China Sea.

In his meeting with Brunei's Sultan Hassanal Bolkiah in San Francisco on Thursday, Xi said China would welcome more exports from Brunei, tell more Chinese enterprises to set up shop in the Southeast Asian country, and expand cooperation in areas such as food security, according to Chinese state media.

Brunei has a claim to part of the South China Sea, most of which Beijing says belongs to China. But unlike some of its vociferous neighbours with claims in the region, Brunei has kept silent on its own claim to a relatively small area off northern Borneo, choosing to focus on growing trade ties with China as the oil-reliant nation diversifies its economy.

"Both sides should work together to promote positive progress in joint maritime development and jointly safeguard peace and stability in the South China Sea," Xi told Brunei's sultan on the sidelines of the APEC summit in San Francisco.

China is willing to work with Brunei and other ASEAN nations to maintain the "correct" direction of cooperation in East Asia, Xi added.

Brunei has counted China as one of its biggest foreign investors and an important force in its efforts to create a more diversified economy, with its crude oil reserves expected to be totally depleted in a few decades.

The largest Chinese investment so far has been a multi-billion dollar oil refinery.

China's Zhejiang Hengyi Petrochemical is a 70% shareholder in the Pula Muara Besar refinery, launched in 2019 in a venture with the Bruneian government.

Hengyi initially invested around $3.45 billion. It subsequently invested a further $13.65 billion to expand the plant's refining capacity and build additional petrochemical facilities.

Brunei's economy is forecast to contract about 1% this year, the International Monetary Fund has said, due to reduced energy production amid infrastructure maintenance. (Reporting by Ryan Woo; additional reporting by Andrew Hayley Editing by Gareth Jones)