China, Japan and South Korea Sunday finalised details of an emergency $120-billion liquidity fund to help 13 Asian economies counter the global economic downturn.

The three nations will contribute on a 2:2:1 ratio - $38.4 billion from China and Japan and $19.2 billion from South Korea - making up 80 per cent of the fund, known as the Chiang Mai Initiative.

Japan has also launched a separate scheme to supply up to 6 trillion yen ($61.5 billion) to support nations hit by the economic crisis.

Both announcements were made on the Indonesian island of Bali, on the sidelines of the Asian Development Bank’s (ADB) annual meeting.

South Korean Minister of Finance Yoon Jeung-hyun told reporters after a meeting with counterparts from China and Japan that Beijing and Tokyo would each contribute 32 per cent to the regional initiative.

South Korea would provide 16 per cent, while the rest would come from the 10-member Association of South East Asian Nations (ASEAN), he said.

The fund will give emergency balance of payments support to any country experiencing the kind of capital flight that marked the Asian financial crisis of 1997-98.

"The three countries have reached an agreement, recognising the importance of our cooperation in the region," said Yoon.