The Office also announced that it will extend the duration and increase the maximum number of applications eligible for the project.

The pilot project began on June 15 last year and was designed to help US patent examiners to assess applications for software patents by encouraging the public to submit relevant prior art.

"Extending and expanding the pilot to include business method patent applications will add more participants to the pilot and help us and the public better assess the effectiveness of Peer Review," said USPTO director, Jon Dudas, in a statement.

A recent report revealed that the project has led to a significant increase in prior art submissions, but has failed to bring in fresh patent applications in its first year.

Companies participating in the peer review programme so far include IBM, Microsoft, Hewlett-Packard, Sun Microsystems, Intel, GE, Red Hat, Cisco and Yahoo!. Goldman Sachs also has volunteered to join following the project's expansion.

Thirty-one applications have been examined to date. Since applications are assigned to an examiner as soon as they are submitted on the peertopatent.org website, the Office says the time to receive a first action is shortened considerably.