The blue-chip index rose 0.6%, with GlaxoSmithKline advancing 5% to become the top gainer after the European Medicines Agency said it was reviewing available data on the use of the company's monoclonal antibody to treat COVID-19 patients.

The gains also came after a report that activist hedge fund Elliott Management took a multi-billion pound stake in the British pharmaceutical firm.

Precious and base metal miners added 2.6% and 1.3%, respectively, as they benefited from higher metal and gold prices. [MET/L] [GOL/]

"I think it's only a matter of time when the FTSE breaches the 7,000 mark," said Michael Hewson, chief market analyst at CMC Markets.

"The catalyst for the game is pretty decent macro numbers out of the U.S., while there is exuberance in minds of the investors with regard to economic recovery and the reopening trade."

The domestically focussed mid-cap FTSE 250 index climbed 0.5%, led by gains in consumer discretionary and industrial stocks.

Britain's biggest building materials seller Travis Perkins gained 2.2% and was one of the biggest boosts to the mid-cap index after it said its first-quarter like-for-like sales, excluding the Wickes unit, rose 17.4%.

The FTSE 100 has gained 8.1% so far this year as investors bet that speedy vaccine rollouts, policy support from the government and businesses reopening would fuel a stronger economic rebound from the pandemic-driven crash.

British gambling group Entain gained 1.1% after its quarterly online net revenue jumped 33%, even as shop closures hit its total net gaming revenue.

(Reporting by Devik Jain and Shashank Nayar in Bengaluru; editing by Uttaresh.V and Aditya Soni)

By Devik Jain and Shashank Nayar