The FTSE 100 ended 0.3% higher with BP, Royal Dutch Shell, Anglo Amercian and Rio Tinto being the top boosts. The domestically focussed mid-cap index added 0.5% to mark its record closing high.

Energy shares, industrial miners and heathcare stocks have been the top three performers this week.

"The resources sector provided some support to the UK's flagship index as mining stocks followed commodity prices higher on a quiet day for corporate news ahead of the August Bank Holiday," said Danni Hewson, financial analyst at AJ Bell.

The FTSE 100 has gained 10.5% so far this year, but continues to underperform its European and U.S. peers as uncertainties due to a global rise in the more contagious Delta coronavirus variant, slowing economic growth, and the risks of central banks paring back support weigh on investor sentiment.

Meanwhile, investors were relived after Powell signalled that the U.S. central banks will remain patient on stimulus tapering as it tries to nurse the economy back to full employment.

"There was no clear announcement of date and pace of tapering. Clearly this is a slightly dovish news," said Matteo Cominetta, an economist at Barings Investment Institute.

Among stocks, British subprime lender Amigo jumped 4.2% after it posted a steep rise in first-quarter profit, although it reiterated there was "material uncertainty" about its ability to continue as a going concern.

Food delivery company Just Eat Takeaway dropped 7.5% to be the top FTSE 100 loser after the New York City Council approved legislation to permanently cap commissions delivery apps can charge restaurants.

Graphic: UK mid-caps outperforms blue-chips this week

(Reporting by Shashank Nayar and Amal S; additional reporting by Sruthi Shankar in Bengaluru; Editing by Subhranshu Sahu and Jonathan Oatis)

By Shashank Nayar and Amal S