Perform buys online rights to major sports events and supplies video clips, live action and sports news and data to media groups and bookmakers. The bid values the company, including Access's existing 42.5 percent stake, at 700 million pounds.

Shares of Perform surged on news of the offer, which at 260p per share matches the price at which the company was floated on the London stock market in 2011. That means those who bought stock three years ago would get their money back after enduring sharp swings in the share price.

Perform shares were up 26 percent to 257.3p by 10:50 AM BST.

"We continue to have confidence in Perform's management and in the company's future potential," said Lincoln Benet, CEO of Access Industries, which was founded by billionaire Blavatnik.

"Consequently, a member of our group is launching an offer at 260 pence per share, a 27.6 percent premium to the current price, to allow those shareholders who seek an exit to do so at a significant premium to the current trading level."

RISE AND FALL

Perform initially established a reputation as a growth stock as it doubled its market capitalisation, before crashing in December 2013 when it issued a major profit warning and saw its shares plunge more than 50 percent in one session.

Access Industries, a privately held industrial group with investments in natural resources, chemicals, real estate and media, including Warner Music Group, said the offer was final.

The group was founded in 1986 by Blavatnik, an American citizen who grew up in Russia.

In an initial response, Perform advised shareholders to take no action for the moment.

"The board reiterates its confidence in Perform Group's standalone strategy and growth prospects as detailed in last Friday's interim results statement," it said.

Perform said on Friday that it was on track to meet revenue and profit targets for the year.

Core profit was 15.6 million pounds in the first half of 2014. Analysts forecast that figure will double in the next six months as cost cuts take effect.

(Reporting by Kate Holton and Keith Weir; Editing by Michael Urquhart and Susan Fenton)