The main index bounced 0.8%, gaining for the third consecutive session, and the mid-caps <.FTMC> gained by the same margin, helped by strong earnings reports.
UK shares, along with their European counterparts, reversed initial losses after a strong open on Wall Street, which was lifted by earnings and strong economic data, despite U.S. curbs on China's Huawei heightening trade tensions.
Miners <.FTNMX1770> jumped nearly 2%, continuing a three-day winning streak, as iron ore futures scaled a record high on strong demand, while aluminium prices also rose as production shutdowns at one of China's biggest smelters fuelled supply worries.
Private equity firm 3i advanced 3.2% after reporting a jump in total returns.
Exporters were also lifted after the pound neared a four-month low as Britain's Prime Minister Theresa May fought to keep her Brexit deal intact, amid growing fears of a disorderly departure from the European Union.
However, Burberry slumped 5.9% on its worst day since January after reporting a drop in adjusted operating profit.
National Grid slipped 3.4% - its biggest one-day drop this year - after reporting a drop in earnings and the opposition Labour Party announced plans to take energy networks back into state ownership if elected.
On the FTSE small-cap index <.FTSC>, Thomas Cook slumped more than 14.7%, after earlier hitting a more than 6-1/2-year low, as the travel group said economic and political uncertainty would hit its profit this summer.
Its larger rival TUI fell 2.5%, while easyJet slipped 2.1% and IAG gave up 1.2%.
The midcap index drew some strong news-related moves.
Livestock genetics firm Genus jumped 14.1% after a deal to license its know-how on virus-resistant pigs to Beijing Capital Agribusiness, which will seek regulatory approval for the pigs in the world's biggest pork market.
Cyber security firm Sophos surged 14% on its best day in more than a year after reporting higher-than-expected annual earnings, while Premier Oil jumped 8.8% as it hiked its production target.
Metro Bank slumped 8.1% after the Financial Times reported that its share placing might be priced at a 10% discount. After the market close Metro Bank announced plans to raise 350 million pounds at a price of 500 pence per share, a 7.3% discount to Thursday's closing price.
(Reporting by Muvija M and Shashwat Awasthi in Bengaluru; editing by Larry King and Alexander Smith)
By Muvija M and Yadarisa Shabong