BEIJING, Oct. 23 (Reuters) – China's promised $10 billion in development funds for Southeast Asia is going to be closer to $1 billion for the time being, diplomats said, ASEAN Leaders Summit got under way in Thailand.

In April, Chinese Premier Wen Jiabao announced China planned to set up a $10 billion China-ASEAN Fund on Investment Cooperation to support infrastructure development in the region.

Details were vague at the time, and little has been heard of the scheme until now.

''The first phase of the fund will be $1 billion and the plan for the total fund will be $10 billion,'' Assistant Foreign Minister Hu Zhengyue told reporters.

''China welcomes other countries, including those in ASEAN, and institutions to join in the raising of these funds.''

Wen, together with Foreign Minister Yang Jiechi, Trade Minister Chen Deming and Finance Minister Xie Xuren,.is attending the second Association of South East Asian Nations summit, after the first one, in April, was called off when protesters stormed the venue in the coastal resort of Pattaya.

This time, the meeting is in the much smaller town of Hua Hin, with China eager to expand its influence in a region with deep historic and cultural ties.

Xue Hanqin, China's ambassador to ASEAN, said that the $1 billion had already been raised for the fund, which will be disbursed through the China Import-Export Bank.

''We hope it will help Asia develop infrastructure and promote balanced development,'' she said.

Xue said Southeast Asian countries were still identifying projects, which would likely include road, rail and port schemes where there were gaps in existing networks.

Hu said the projects could include large-scale energy and resource sector projects.

ASEAN groups Brunei, Indonesia, Malaysia, the Philippines, Singapore, Thailand, Vietnam, Myanmar, Laos, and Cambodia.

China and the 10-member regional group together account for about one-third of the world's population and one-ninth of global GDP.

China is the eighth biggest investor in ASEAN, with outstanding two-way investment totalling $11.7 billion at the end of 2008. A Free Trade Agreement between ASEAN and China, its fourth-largest trading partner, will come into effect on Jan. 1.

Trade ties, regional security, disaster relief and human rights will likely dominate this week's summit .