By Carla Mozee, MarketWatch

U.K. stocks slipped Thursday, with the benchmark FTSE 100 limited by losses among mining stocks and by shares of GlaxoSmithKline PLC after the drug maker was downgraded.

After dropping as low at 0.9%, the FTSE 100 was off less than 1 point at 6,949.11. Indexes in the broader European markets have also appeared listless during the session, in part as some bourses were closed for the Ascension Day holiday (http://www.marketwatch.com/story/which-markets-are-closed-for-ascension-day-2015-05-14), and as investors await further clues on the direction of interest rates in the U.S., the world's largest economy.

Jobless-claims data from the U.S. due later Thursday "should give investors something to react to," with the market looking for "further evidence of the labor market recovery," said Craig Erlam, senior market analyst at Oanda, in a note.

A slate of weaker-than-expected U.S. economic data on Wednesday drove the U.S. dollar lower, benefiting the greenback's rivals including the pound (GBPUSD). Sterling was up at $1.5786 on Thursday from $1.5745 late Wednesday in New York.

On the FTSE 100, the heavily weighted mining sector was down more than 1%, with some London-listed firms following up on declines in Asian trade overnight. Shares of iron-ore producers BHP Billiton PLC (BHP) fell 1.5% and Rio Tinto PLC (RIO) gave up 1.3%.

"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 Anglo American PLC dropped 2.7%, Antofagasta fell 0.8% and Glencore PLC (GLCNF) shed 0.6%.

Elsewhere, Glaxo (GSK) shares fell 0.8% 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 were moving lower, down 1.7%.

Advancers on the FTSE 100 included Hikma Pharmaceuticals PLC . Shares rose 1.7% after the company backed its forecast for 2015, and said its U.S. injectables business is performing well, "with strong sales of certain products offsetting increased competition on other products."

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