The US Supreme Court says Bernard Ebbers, former chief executive at WorldCom, will remain in prison to serve out his 25-year sentence.

The court turned down an appeal by Ebbers yesterday without comment. The appeal was based on Ebbers' belief he did not receive a fair trial because potential defence witnesses were not offered immunity as were prosecution witnesses.

Ebbers is serving out his term at the Oakdale Federal Correction Complex after reporting to prison in July following the US Court of Appeals decision to uphold his original conviction, which was handed down in September 2005. He was convicted by a jury of orchestrating an $11 billion accounting fraud in in March 2005.