Phnom Penh  - State-owned Japan Oil, Gas and Metals National Corp has formally committed to invest 4.5 million dollars in a joint venture in Cambodia with the Australian gold-exploration company Southern Gold Ltd, the company said Monday.

Adelaide-based Southern Gold said in a statement to the Australian Securities Exchange that the deal would accelerate exploration on three Cambodian gold and base-metal projects in the north-east of Cambodia.

The announcement confirmed a March letter of intent.

Under the now formal terms, the Japanese firm must spend a minimum of 1 million dollars on the projects over the next 12 months and would make a total investment of 4.5 million dollars over three years to earn a 51-per-cent interest in the three tenements, it said.

Southern Gold has previously posted promising gold and base-metal predictions on the three projects from early exploratory research.

The Japanese firm said its objectives in the deal were securing a stable supply of oil, natural gas, nonferrous metals and minerals for Japan and, if exploratory results were positive, the equity interest would be transferred to a private-sector Japanese company.

Southern Gold's other investors in the project include Chinese resource investor CITIC as well as Australia's Macquarie Bank Ltd. (dpa)