The FTSE 100 was up 0.5 percent and the FTSE 250 rose 0.2 percent by 0904 GMT to cling to a six-month high hit in the previous session. But trading remained muted before the start of the US corporate earnings season.

Plus500 slumped more than 25 percent and hit its lowest level in almost two years after its quarterly revenue plummeted to below a fifth of a year earlier. It took a hit from less market volatility creating fewer trading opportunities and new rules affecting retail clients.

Its mid-cap peer IG Group dropped 2.5 percent and CMC Markets gave up 5.8 percent.

Trading remained light as investors reflected on a week that saw Britain secure a second Brexit delay and they awaited financial reports from US bellwethers JP Morgan and Wells Fargo, in light of re-emerging fears of a global economic slowdown.

Expectations for the US earnings season were low, said CMC Markets analyst Michael Hewson. "The global economic outlook continues to look a little on the soft side, even without this week's IMF growth downgrades," he said.

China reported a mixed set of data on Friday, with March exports rising more than expected and imports declining more than expected.

Miners Rio Tinto and Glencore added more than 1 percent and were the biggest boosts to the main index as copper prices rebounded. Spreadex analyst Connor Campbell also attributed the rise to data showing China's iron ore imports rose in March after touching a 10-month low in February.

Separately, data from China's central bank showed that new loans and total lending surged in March, suggesting months of policy loosening were starting to bear fruit. Asia-focussed heavyweight banks HSBC and Standard Chartered were among the top boosts to the main index as a result.

Among the few blue-chip stocks in the red was British American Tobacco, which slid 1.5 percent and was on course for its sixth straight session of losses.

Mid-cap Pets At Home tumbled 11.2 percent, on course for its biggest one-day loss since May 2018, after Canada Pension Plan Investment Board agreed to sell its holding in the company, almost 11 percent of the shares.