Blinkx, whose video search engine competes against the likes of Yahoo! Video and Google Video, generates revenue through online advertisers and says that 168 million people a month use its search technology in the United States. That compares with 100 million worldwide in March.

The company, which has partnerships with web portal AOL and mobile device maker Samsung, is one of this year's top performers on the FTSE AIM 100. Its shares have risen by 180 percent since the start of the year, against a 30 percent gain for the wider index.

Blinkx shares were up 16 percent by 1404 GMT at a record 195 pence.

"This has been an exciting first half for Blinkx," Chief Executive Subhransu Mukherjee said after announcing a forecast-beating 76 percent leap in core earnings.

"The business continues to demonstrate robust underlying growth and stability."

Blinkx reported earnings before interest, tax, depreciation and amortisation (EBITDA) of $18.2 million in the six months to September 30.

Citi and Numis analysts had been expecting EBITDA closer to $11 million.

Jefferies analysts said in a note: "A fast-moving space, we see the financially robust as prospective winners. Today's revenue growth, gross margin, EBITDA margin, cash and cash conversion mark Blinkx as such."

About 15 percent of Blinkx users access the technology on mobile devices and CEO Mukherjee said he expects advertising on mobile platforms to be a big driver for the company's future growth.

He also said that emerging markets will become increasingly important to the group, though it could be a few years until advertising revenue begins to make an impact.

"While the growth of users, particularly in mobile devices, is really at stratospheric levels in the emerging markets, the truth is that the advertising dollars behind that is still in an embryonic stage," he said.

Blinkx was founded by Autonomy in 2004 and listed on London's AIM market in 2007. Autonomy, now owned by U.S. computer group Hewlett-Packard, sold its remaining Blinkx stake in June this year for 55 million pounds ($88 million).

(Editing by David Goodman)

By Joshua Franklin