Shares in British Gas owner Centrica rose 4% following a report that it could be a bid target.
A report on the Wall Street Wires website said there was talk that the company had attracted the interest of a couple of potential buyers.
Centrica was the biggest riser on the FTSE 100, with the index up 1.02 points at 7,338.30 shortly after midday.
Shares in Easyjet rose 3.9% after Credit Suisse raised its rating on the airline to “outperform” from “neutral”.
In the FTSE 250, shares in homewares retailer Dunelm rose 5.5% after it reported strong fourth quarter trading.
Total revenues for the 13 weeks to 1 July rose 17.7% to £340m, helped by the company’s takeover of home improvement products retailer Worldstores. Like-for-like sales in the quarter were up 3.8%.
However, Dunelm said it expected full-year pre-tax profits to be between £109m and £111m, down from £128.9m last year.
On the currency markets, the pound fell 0.6% against the dollar to $1.2896 following the release of several weaker-than-expected pieces of economic data.
Office for National Statistics data showed that manufacturing and construction output fell in May, and the trade deficit widened.
Against the euro, sterling was down 0.4% at 1.1301 euros.