Hikma shares were the biggest blue-chip gainers after a target price update from Jefferies, adding 3.6 percent to the 11.6 percent jump on Tuesday, when it announced a deal to buy Boehringer Ingelheim's U.S. generic drugs business Roxane for about $2.65 billion in cash and stock.

"The deal has created a firm foundation for future growth," Augustin Eden, analyst at Accendo Markets, said. "Hikma shares could be bound for a return to February highs and above - still a healthy 8.5 percent away despite gains of yesterday."

The blue-chip FTSE 100 index <.FTSE> was up 0.7 percent at 6,601.92 points by 1339 GMT, after rising 0.8 percent in the previous session when it snapped a five-day losing streak.

Drugmaker GlaxoSmithKline rose 2.8 percent after flagging up dozens of new drugs and vaccines in development as demand for new HIV medicines helped it beat quarterly profit forecasts.

Barclays shares rose 2 percent after the bank, which reported a 12 percent rise in profit, said it intended to accelerate the sale of assets and cost cutting.

"Barclays appears eager to press ahead with the increased pace of restructuring ... Most of the key metrics continue to show improvement, with a reduction in operating expenses and impairments being complemented by another robust income showing, leading to a notable hike in adjusted profits," Richard Hunter, head of equities at Hargreaves Lansdown, said.

"In addition, the capital cushion remains comfortable and the return on equity is showing some signs of life."

British American Tobacco was up 3.2 percent after reporting a better-than-expected performance for the second quarter.

Small-cap Quintain Estates and Development jumped 23 percent on news that it is to be bought by U.S. private equity firm Lone Star after receiving a bid valuing the firm at around 700 million pounds ($1.1 billion)..

On the downside, Compass Group fell 4.8 percent after the world's biggest catering firm said operating profit this year and next would be hit by restructuring costs.

Mid-cap engineering supply group Premier Farnell slumped 17 percent following comments that it expected a 10 percent fall in first-half adjusted operating profit after sales growth per day in its main markets slowed in the second quarter.

(Editing by Alison Williams and Susan Thomas)

By Atul Prakash and Liisa Tuhkanen