The UK benchmark showed little reaction to data showing Britain's economy is bigger than previously estimated.

Britain's No. 2 clothing retailer fell 4.3 percent, the top blue-chip decliner in brisk trade, after saying the country's unusually warm autumn weather was deterring shoppers from buying winter clothing.

Its third-quarter sales to date were up 6 percent, lower than its previous forecast of up 10 percent. Trading volume in Next stood at twice its 90-day daily average against just a quarter seen on the FTSE 100.

"Next does not often lower guidance. So the fact that they have said they may do so due to the warmer weather is hitting the shares, which have had a strong run, and will also hit the sector if the weather remains unseasonal," Securequity sales trader Jawaid Afsar said.

The weather warning put pressure on other retailers, with Marks & Spencer falling 2 percent to be the second biggest decliner in the benchmark share index. Midcap Debenhams fell 2.9 percent.

The FTSE 100 was down 4.81 points, or 0.1 percent, at 6,641.79 points by 0959 GMT. The index, which dropped 2.8 percent last week, is down about 1.5 percent so far this year.

"We continue to highlight the bearish possibility of more downside given the increase in concerns over the last week," Accendo Markets head of research, Mike van Dulken, said.

Investors stayed cautious following soft manufacturing data from China, the world's biggest metals consumer, and civil unrest in Hong Kong, where tens of thousands of pro-democracy protesters extended a blockade of streets.

On the positive side, testing company Intertek jumped 3.8 percent after appointing a new chief executive to replace retiring chief executive Wolfhart Hauser.

Andre Lacroix will join from multinational car dealer Inchcape, where he has been chief executive since 2005.

Shares in midcap Inchcape fell 4 percent.

Royal Bank of Scotland also notched up good gains after saying it will release a substantial amount from provisions it had set aside to cover losses on bad loans.

RBS rose 2.7 percent after the state-backed bank said it will release 800 million pounds from provisions after an improvement in the economy, especially in Ireland.

(Additional reporting by Sudip Kar-Gupta; Editing by Alison Williams)

By Tricia Wright and Atul Prakash