Britain's Serious Fraud Office (SFO) has frozen $US100 million (£60 million) of UK assets related to Allen Stanford, the Texan billionaire facing charges of fraud.

"I am delighted the SFO has been able to secure a freezing order of this magnitude and within five hours of it being requested," Richard Alderman, the SFO director, said. "I am determined that supporting our US counterparts in this way becomes a routine example of cross-border co-operation."

Last week Stanford appeared in a Houston court, handcuffed in an orange jump suit, and pleaded not guilty to charges of fraud, conspiracy and obstruction. He stands accused of fraud totalling US$7 billion (£4.3 billion), and the charges include seven counts of wire fraud, 10 counts of mail fraud, conspiracy to obstruct an investigation for the Securities and Exchange Commission, obstruction of an investigation by the SEC and conspiracy to commit money laundering.

A federal judge will, later on Tuesday, decide on bail for Stanford, which would see him freed while he awaits trial.

If convicted, he faces up to 375 years in jail.