(Adds details from indictment and about London civil trial, background on Autonomy acquisition, comments, case citation, byline)
By Jonathan Stempel
March 22 (Reuters) - U.S. prosecutors on Friday added three new criminal charges to their indictment against British entrepreneur Mike Lynch related to the $11.1 billion sale of his software company Autonomy to Hewlett-Packard in 2011.
Lynch faces a new charge of securities fraud, which carries a maximum prison term of 25 years, as well as additional charges of wire fraud and conspiracy in the 17-count indictment filed with the federal court in San Francisco.
The charges were revealed ahead of Monday's scheduled start of a $5 billion civil fraud trial in London's High Court, where HP is accusing Lynch and former Autonomy Chief Financial Officer Sushovan Hussain of involvement in accounting irregularities that caused it to overpay for the company.
Lynch has denied wrongdoing, and blamed the failure of the acquisition on HP management.
The wire fraud and conspiracy charges were also added against Lynch's co-defendant Stephen Chamberlain, a former Autonomy vice president of finance.
Lawyers for Lynch and Chamberlain did not immediately respond to requests for comment.
The Autonomy purchase was the centerpiece of a strategy by Leo Apotheker, HP's chief executive at the time, to refocus his company on business services and products.
But the purchase soured a year later when HP wrote off $8.8 billion for Autonomy and accused Lynch, who founded that company in 1996, and his colleagues of accounting fraud.
The new securities fraud charge accuses Lynch of defrauding investors in connection with the purchase and sale of HP securities.
A federal jury in San Francisco convicted Hussain last April of wire fraud and other crimes tied to Autonomy's valuation. Hussain's sentencing is scheduled for May 13, and he has been expected to appeal the verdict.
The U.S. case is U.S. v. Lynch et al, U.S. District Court, Northern District of California, No. 18-cr-00577. (Reporting by Jonathan Stempel in New York; Additional reporting by Paul Sandle in London; Editing by G Crosse and Paul Simao)