(Corrects typographical error in first paragraph)
* FTSE up 0.1 pct as Q2 UK GDP is revised up
* Bernanke comments eyed
* Tullow down after reports it failed to get license renewal
By David Brett
LONDON, Aug 27 (Reuters) - Britain's top share index was up by midday on Friday, off a seven-week low earlier this week, after the UK's second-quarter gross domestic product was unexpectedly revised upwards and ahead of a speech from U.S. Federal Reserve Chairman Ben Bernanke.
By 1041 GMT, the FTSE 100 <.FTSE> was up 2.94 points, or 0.1 percent, at 5,158.78, having closed up 0.9 percent at 5,155.84 in the previous session, rallying from a seven-week closing low on Wednesday.
Britain's economy grew faster than originally estimated in the second quarter of this year, reaching its fastest rate of growth in more than nine years, official data showed on Friday.
The Office for National Statistics said the economy grew by 1.2 percent in the three months to June, up from its preliminary estimate of 1.1 percent, after construction output proved stronger than first thought. Analysts had expected no revision.
"What we continue to see is nervousness revolving around the potential for a weaker growth profile hitting investor sentiment and eating away at investors' risk appetite on one side," Henk Potts, equity strategist at Barclays Wealth, said.
"But on the other side you've still got demonstrations of a relatively strong corporate picture. I suppose when you get those two concepts meeting, inevitably you'll result in an element of volatility."
Tullow Oil
Other energy stocks <.FTNMX0530> fell in tandem with crude
prices
Banks <.FTNMX8350> were also weaker as risk appetite
deserted investors, with Lloyds Banking Group
EYE ON JACKSON HOLE
Fed Chairman Bernanke is scheduled to give a keynote speech later on Friday at a conference of central bankers from around the world in Jackson Hole, Wyoming.
In the speech, he is likely to signal his views about the uncertain prospects for the world's biggest economy but probably will not offer many clues on whether the U.S. central bank will pump in more cash to keep the recovery going. [ID:nN25199098]
Rolls-Royce
Thin seasonal trade accentuated many of the share price
moves on the FTSE 100, as Cable & Wireless Worldwide
"We're just seeing light volumes ... But all eyes on the States and Bernanke later on this afternoon," Giles Watts, head of equities at City Index, said.
National Grid