UK stocks opened substantially stronger on Friday, recouping a portion of Thursday's steep losses, though investors remained on edge about trade tensions between the US and China.

At 0844, the benchmark FTSE 100 index had risen 109.04 points, or 1.6%, to 6.813.09.

Associated British Foods fell 2.4% amid a warning that its clothing chain Primark encountered a 'tough' retail backdrop. The company, however, still stuck to its full-year guidance for flat adjusted earnings.

High-end housebuilder Berkeley Group gained 2.7% as it raised its full-year profit guidance, despite reporting first-half profit fell by more than quarter amid a slowdown in the London housing market.

AstraZeneca said a clinical trial evaluating the efficacy of its head and neck cancer treatment failed to meet its primary goal of improving death rates. Its shares, however, rose 0.7%.

Board games retailer Games Workshop gained 4.6% on announcing its first-half performance was in-line with expectations, keeping it on track to meet full-year guidance.

Video games company Team17 said it would launch shooter game Genesis Alpha One on 29 January. Its shares rose 0.8%.

Premier Oil climbed 4.7% as it stuck to its annual production guidance, having achieved higher-than-expected output in November and December.

Filtration and environmental technologies group Porvair rallied 6.5% on announcing that it expected to post annual earnings ahead of its expectations, while revenue would grow by around 10%.

Information and analytics company Relx gained 1.7% after it completed its £700m share buyback programme for 2018 and said it would repurchase another £100 worth of shares early in the new year.

Ophir Energy gained 2.7% on news an exploration well in Indonesia had discovered natural gas.

President Energy said oil had successfully flowed during testing operations from the second well at its prospects at Rio Negro province in Argentina. Investors weren't surprised and the shares fell 0.5%.