San Francisco - Blinkx, a searchable index of Web video, saw its shares rise 40% in their initial public offering on the London Stock Exchange Tuesday, which garnered around $50 million and saw the company valued at nearly $355 million.

Cambridge, U.K. - Autonomy, a provider of enterprise and consumer search technology, announced on Wednesday that it will exercise an option to buy consumer video search provider Blinkx, merge its own consumer search division with the company, and file for an initial public offering on London's AIM exchange next month.