JAKARTA, April 19 (Reuters) - Indonesian plantation company PT Bakrie Sumatera Plantations Tbk plans to jointly build the country's first biodiesel plant to meet a surge in demand for renewable energy, the company said.

Bakrie Sumatera would build the $25 million factory in a joint venture with construction firm PT Rekayasa Industri, a company statement said.

The plant would have the capacity to produce between 60,000-100,000 tonnes of biodiesel a year as a substitute for diesel fuel.

Bakrie will have 70 percent of the venture, to be called Bakrie Rekin Bio-Energy, and Rekayasa Industry the remainder.

The Jakarta Post newspaper reported construction will begin early next year, with the plant expected to come onstream in mid-2008.

The paper quoted Bakrie President Director Ambono Janurianto as saying his company, which manages 31,000 hectares of oil palm plantations in Jambi, will provide the raw material for the biodiesel, including crude palm oil and other feedstock.

Bakrie Sumatera Plantations has a market capitalisation of $184.51 million and is part of the group controlled by the family of Indonesian chief welfare minister Aburizal Bakrie.

Indonesia, a member of the OPEC oil producers' cartel but forced to import a quarter of its fuel, is scrambling for alternative energy sources as its oil and gas reserves dwindle and soaring world oil prices increase the burden of its fuel subsidies.

According to Rekayasa Industry's president director, the country consumes around 27 million kilolitres of diesel each year, 30 percent of which is imported.

In October, the government hiked domestic fuel prices in an attempt to ease pressure on its budget, sending inflation to a six-year high and driving up interest rates.