Silicon Valley companies considering going public are increasingly looking to London's AIM exchange, rather than Nasdaq, the Financial Times reports. Why? First and foremost, Sarbanes Oxley.

More than 100 US companies are thinking about listing on AIM instead of Nasdaq, the paper says. The interest started about six months ago and grows daily, said Gary Benton of the Palo Alto law firm of Pillsbury Winthrop Shaw Pittman. "We get a phone call from an interested company almost every day at the moment.”

Venture capitalists have reached a breaking of frustration with the high costs of launching companies. Tim Draper says it now takes 10-12 years, instead of 5-7 years, to go from startup to IPO.

A lot of the entrepreneurs I’ve talked to who have very successful companies…are going to take them public on the London exchange or the Singapore exchange or the Hong Kong exchange.

The first Valley company to list on AIM is OCZ, a maker of memory technologies. They raised $9.4 million on AIM when they listed in June. And SOX was the main reason they chose AIM instead of Nasdaq.

“Sox is a big impediment for companies of our size, with bills of $2m to $4m to raise the money and then get a first-year sign-off [of accounts by auditors]," said CFO Arthur Knapp.