By Carla Mozee, MarketWatch

U.K. stocks finished higher Thursday, gaining alongside broader European markets after the European Central Bank's boss said monetary stimulus for the eurozone will continue as long as it is needed.

The FTSE 100 gained 0.3% to finish at 6,973.04, after dropping as low at 0.9% earlier in the session. But equities found firmer footing in afternoon trade after weekly U.S. jobless claims unexpectedly dipped, suggesting U.S. employment strength, and remained at a 15-year low. U.S. stocks jumped (http://www.marketwatch.com/story/us-stocks-set-for-solid-open-with-jobless-claims-ppi-in-view-2015-05-14)at the opening of trade.

U.K. stocks, and more broadly European markets (http://www.marketwatch.com/story/european-stocks-lower-as-euro-climbs-above-114-2015-05-14), rose further after ECB President Mario Draghi, in a speech in Washington (http://www.ecb.europa.eu/press/key/date/2015/html/sp150514.en.html), said the bank remains committed to providing monetary policy support for the eurozone economy. The Stoxx Europe 600 rose 0.6% to 397.99.

The European Union represents the U.K.'s biggest trading partner.

The ECB in March launched EUR1.1 trillion bond-buying program aimed at beating deflation risks and encouraging economic growth, and "quite some time is needed before we can declare success," said Draghi. Monetary policy stimulus "will stay in place as long as needed for its objective to be fully achieved on a truly sustained basis," he said.

The FTSE 100's gain was limited in part by losses among mining stocks, with some London-listed firms following up on declines in Asian trade overnight. Shares of iron-ore producers BHP Billiton PLC (BHP) fell 1.3% and Rio Tinto PLC (RIO) gave up 0.8%.

"The run iron-ore miners had experienced now seems to have come to a screeching halt as the retreat in iron-ore prices and a higher [Australian dollar] takes a toll," Stan Shamu, market strategist at IG, wrote Thursday.

Also lower, miner Antofagasta fell 0.4% and Glencore PLC (GLCNF) shed 0.2%.

Elsewhere, GlaxoSmithKline PLC (GSK) shares slipped 0.1% following a ratings downgrade at UBS to neutral from buy. Glaxo last week abandoned plans to spin off its HIV-drugs focused Viiv Healthcare division. UBS said Glaxo's 2020 pharmaceuticals outlook "implies sharp deterioration of pharma margin," excluding ViiV.

ITV PLC posted higher revenue for its first quarter (http://www.marketwatch.com/story/itv-posts-rise-in-revenue-2015-05-14), but shares ended down 1%.

Advancers on the FTSE 100 included Hikma Pharmaceuticals PLC . Shares rose 2.4% after the company backed its forecast for 2015 (http://www.marketwatch.com/story/hikma-pharmaceuticals-good-start-to-the-year-2015-05-14).

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