A tech entrepreneur facing fraud charges in the US for allegedly overstating the value of his company ahead of its sale has been bailed on a £10m security ahead of his extradition fight. 

Electrical engineering expert Michael Lynch, 54, sold his software company Autonomy to Hewlett-Packard (HP) in 2011 for $11 billion.

But the sale resulted in heavy losses for the US firm. 

US authorities claim he deliberately overstated the value of his firm, which specialised in software to sort through large data sets. 

A US extradition request for the businessman - who has a PhD in signal processing from the University of Cambridge - was submitted to British authorities in November. 

He faces 17 criminal charges including wire fraud, securities fraud and conspiracy to defraud. 

HP is seeking damages of $5 billion from Lynch in a civil case in London's High Court. 

He claims any loss was down to the tech giant's mismanagement of the acquisition. 

At a hearing at Westminster Magistrates' Court this morning, Judge Emma Arbuthnot granted Lynch bail on the condition a security of £10m be placed with the court.

Lynch's legal team had initially offered £1.5m. 

Alex Bailin QC, for Lynch, said his client had not left the country since learning of the extradition bid more than a year ago and has handed over his British and Irish passports. 

He said Lynch divided his time between London and his family's farm in Suffolk. 

"This is UK-based conduct, a UK-based plc culminating in a UK civil trial. This matter is unquestionably based in the UK - the forum bar (of the Extradition Act 2003) is there to provide real protection," he said. 

Mr Bailin said the indictment against Lynch spanned almost 10 years, and described it as "breathtakingly broad". 

Judge Arbuthnot listed Lynch's case for a management hearing on March 10 ahead of a full hearing later this year.

On top of the £10m security, she barred him from applying for any international documents, leaving England and Wales, or entering any international airport, ferry port or train terminal. 

Lynch, who has a house in Chelsea, was also ordered to attend Belgravia Police Station every Friday. 

"If you fail to comply you could face up to a year in prison - possibly more," Judge Arbuthnot told him.

In a joint statement, Lynch's lawyers Chris Morvillo and Reid Weingarten said the allegations had previously been investigated by the UK's Serious Fraud Office and no action was taken. 

"The US Department of Justice should not have commenced extradition proceedings prior to the judgment of the English High Court," they said. 

"This case has wider implications for British business. The US claims concern alleged conduct in the UK. Dr Lynch is a British citizen who ran a British company listed on the London Stock Exchange, governed by English law and UK accounting standards," they said. 

"This extradition request reflects yet another example of the Department of Justice's attempts to exert extraterritorial jurisdiction over non-US conduct," they added.

"The forum bar in the UK Extradition Act was enacted by the UK Parliament to protect British citizens from such a scenario. Dr Lynch vigorously rejects all the allegations against him and is determined to continue to fight these charges," they concluded.