BANGKOK - THAILAND'S Supreme Court on Monday agreed to hear a fourth case against Thaksin Shinawatra, accusing the ousted and exiled Thai premier of amending tax policy to enrich his business empire.

Thaksin fled to Britain with his family last month claiming he would not get a fair trial on the corruption charges mounting against him, but prosecutors have forged ahead with the cases.

'The court has found that this case is in the court's jurisdiction,' Judge Pongphet Vichitchonchai said, setting the first hearing for October 15.

The case accepted on Monday is related to Advanced Info Service (AIS), one of Thailand's biggest mobile phone operators and a subsidiary of Shin Corp, the telecoms giant founded by Thaksin.

An anti-corruption body set up by the junta which overthrew Thaksin in September 2006 has accused Thaksin of changing a telecoms concession fee into an excise tax in 2003, saving AIS money in a concessions deal.

Thaksin eventually sold his family's stake in Shin Corp to Singapore's state-owned investment unit Temasek for almost 1.9 billion dollars (S$2.7 billion).

The January 2006 tax-free sale sparked massive street protests that eventually culminated in the 2006 coup.

Most of the money linked to the sale - about 76 billion baht (S$3.13 billion) - has been frozen by the anti-graft body.

The Supreme Court is due on September 17 to decide whether Thaksin and his wife Pojaman are guilty of collaborating to enable Pojaman to purchase a prime piece of real estate at a cut price.

Pojaman was on July 31 convicted of tax evasion and sentenced to three years in jail. She appealed, but analysts have said the court decision against her stunned Thaksin and helped spark the couple's flight into exile.

The Supreme Court has issued arrest warrants against both Thaksin and Pojaman for skipping a required court appearance. -- AFP