Source: Sharecast
The FTSE 100 was called to open around 15 points higher.
Data released earlier by the Office for National Statistics showed that economic growth slowed in the second quarter, albeit less than expected.
The economy grew 0.3% following 0.7% growth in the first quarter, and versus expectations for a 0.1% expansion.
Liz McKeown, director of economic statistics at the ONS, said: "Growth slowed in the second quarter after a strong start to the year.
"The economy was weak across April and May, with some activity having been brought forward to February and March ahead of stamp duty and tariff changes, but then recovered strongly in June.
"Across the second quarter as a whole growth was led by services, with computer programming, health and vehicle leasing growing.
"Construction also increased while production fell back slightly.
"Growth for the quarter was also boosted by updated source data for April, which while still showing a contraction, was better than initially estimated.
"Services also drove growth in June with scientific R&D, engineering and car sales all having a strong month.
"Within production, which recovered, manufacture of electronics performed especially well."
In corporate news, National Grid said it had sold its Grain LNG business to a consortium of Centrica and Energy Capital Partners, part of Bridgepoint Group, for £1.66bn.
Grain LNG owns and operates the UK's largest liquefied natural gas importation terminal under long term take or pay contracts.
Insurance firm Admiral delivered a robust set of interim results, with growth in customer numbers and a continued focus on pricing discipline helping to offset sector-wide pressures.
Admiral said pre-tax profits from continuing operations jumped 69% to £521.0m, driven by standout performances in UK Motor, Household, and Admiral Money, with insurance revenue rising 18% to £2.47bn and gross loan balances at Admiral Money climbing 25% to £1.28bn.
Copper miner Antofagasta reported a 60% surge in first-half profits on the back of increased output and materially lower costs, helping to drive margins to their highest in four years.
EBITDA totalled $2.23bn in the six months to 30 June, up from $1.39bn the year before, with revenues rising 29% to $3.80bn. The company also more than doubled its interim dividend per share to 16.6 cents from 7.9 cents.