Black was convicted in July 2007

Former media tycoon Conrad Black is appealing to US President George W Bush to commute his prison sentence for fraud and obstruction of justice.

Black, a Canadian-born member of the UK's House of Lords, has been in prison since March, serving a sentence of six and a half years.

The US justice department confirmed it had received the appeal and said it would be considered in the normal way.

Mr Bush has the power to issue a pardon and reduce a prison sentence or fine.

The US Pardon Attorney, Ronald Rogers, will investigate and review the appeal, and make recommendations to the president.

Of approximately 10,000 petitions received by the Pardon Attorney, only 163 have resulted in a presidential pardon or reduced sentence.

Black and three other executives were convicted of defrauding shareholders of one-time newspaper publishing giant Hollinger International Inc.

A US federal appeals court unanimously upheld his conviction this summer.

He is serving his sentence in Florida's largest prison, the Coleman Federal Correctional Complex.

Details of the appeal were not immediately available.