Britain's top share index inched higher on Tuesday as investors remained cautious ahead of a Spanish bill auction later in the session, while Burberry and Marks & Spencer retreated after their respective updates.

The UK blue chip index <.FTSE> was 6.89 points, or 0.1 percent, higher at 5,673.17 at 0711 GMT, having added 0.3 percent on Monday helped by narrow gains from defensive stocks and after positive U.S. retail sales data, although rising debt yields for Spain kept banks on the backfoot.

It appears that investors may be holding fire ahead of Spain's (debt) auctions which begin today, Ian Williams, UK equity strategist at Peel Hunt, said.

Sector leadership ... is still difficult to find but the upward revisions and low risk styles continue to make steady, if modest, progress, he said.

British luxury brand Burberry Group fell 3.9 percent as it met forecasts with an 18 percent rise in second-half sales. Burberry's shares have outshone the benchmark in 2012, rising 33.8 percent as investors have turned to the company's growth charecterstics spurred by exposure to Asia markets.

Bellwether British retailer Marks & Spencer shed 2.7 percent as it missed forecasts for underlying fourth-quarter sales, with growth in food sales failing to offset a weaker outcome in general merchandise.

(The first paragraph is corrected to show Spanish auction is of bills not bonds)