Indonesia picked China over Japan to build the country's first fast-train rail link because Beijing had the courage to provide $5 billion in loans without asking for guarantees, an Indonesian official said on Wednesday.

The two Asian giants had been battling for months over the high-profile contract to build a railway linking the Indonesian capital, Jakarta, with the textile hub of Bandung.

Indonesia initially envisaged a high-speed service for the 150-km journey but changed its mind last month, opting instead for a medium-speed train. Analysts have said whoever won the bid could be a front-runner for future rail projects in the region, including one linking Kuala Lumpur and Singapore.