By Barbara Kollmeyer, MarketWatch

MADRID (MarketWatch) -- Britain's benchmark stock index gained ground Friday with the mining sector buoyed by growth data from China, as shares of Rio Tinto PLC rebounded a day after taking a massive write-down.

The FTSE 100 index rose 0.6% to 6,168.29, following a 0.5% gain Thursday after markets drew support from stronger U.S. economic data.

Miner Rio Tinto PLC (RIO) was among London's heavy hitters moving higher on Friday, it shares adding 2.7% after having lost 0.5% on Thursday. It had been hit even harder earlier in Thursday's session, on the back of a $14 billion impairment charge and the exit of its chief executive.

Analysts at Barclays Research said Friday that the departure of Tom Albanese as CEO and the write-downs will herald a new era for the company.

"We believe these decisions are an attempt by Rio's board to draw a line under the past five years of poor capital allocation in M&A and re-establish themselves as the industry leader in cost control both capital and operational," the analysts said in a note.

Separately, Goldman Sachs said Rio is now "looking for some goodwill in the market. To that extent, we believe Rio may look to give shareholders what they want, which is cash back." The potential of a buyback being announced in Rio Tinto's full-year results has risen, they said.

News of stronger-than-expected growth out of China underpinned London's mining sector.

In the U.K., however, retail sales rose at their slowest annual pace for two years in December, adding to worries the economy shrank in the final quarter of 2012.

Also Friday, Barclays upgraded Meggitt PLC to overweight from equalweight, saying that a valuation discount for the engineering company that specializes in aerospace equipment -- pegged at 20% to its peers -- is due to close.

That will come as investors in the aerospace cycle look away from pricier pure-play names, the brokerage said, calling Meggitt as well as U.S-based Rockwell Collins Inc. (COL) good late-cycle plays. Barclays lifted its price target on Meggitt by 16%, to 520 pence.

Meggitt's shares rose 2%.

Among other movers in London, shares of Diageo PLC (DEO) rose 1.3%, while consumer-goods conglomerate Unilever PLC (UL) gained 0.4%.

On the downside, shares of J Sainsbury PLC fell 0.8%. Goldman Sachs added the grocery chain to its conviction sell list, saying cash flow and balance sheets are at risk as momentum slows.

Subscribe to WSJ: http://online.wsj.com?mod=djnwires