By Sara Sjolin, MarketWatch

LONDON (MarketWatch) -- Shares of Barclays PLC climbed to the top of the U.K. benchmark stock index on Wednesday, standing out in an otherwise downbeat market where the trading mood was subdued after a new round of sanctions on Russia.

The FTSE 100 index lost 0.5% to close at 6,773.44, after posting a 0.3% gain on Tuesday.

Barclays (BCS) put on 4.2% after the bank said it swung to a profit in the second quarter. Chief Executive Antony Jenkins said the company is making progress in slimming down the business, an effort to make it less dependent on its investment banking division.

Travis Perkins PLC climbed 2.7% after the building materials supplier posted a 14.1% increase in first-half pretax profit.

On a more downbeat note, shares of Antofagasta PLC lost 4.6% after the miner said it was on track to meet its full-year guidance, but that cash costs rose in the second quarter.

Tullow Oil PLC slipped 1.1% after the oil explorer said it swung to a loss in the first half of the year.

More broadly, investors were cautious in moving further into the stock market as they analyzed the consequences of tougher sanctions on Russia. The U.S. and European Union said late Tuesday they would impose stricter restrictions on the country, targeting its energy, banking and defense sectors.

In U.K. specific news, the Bank of England's Prudential Regulation Authority laid out new rules designed to claw back banker bonuses up to seven years after they are received. The pay back would happen if an employee was found to have misbehaved or contributed to a failure in risk management.

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