Burberry nudges FTSE 100 higher; profit alert hits A.G.Barr

London's main stock market index inched higher on Tuesday, helped by gains in healthcare shares and Burberry, which surged after its first-quarter update showed new designs from creative chief Riccardo Tisci were boosting sales.

The FTSE 100 added 0.1% and the mid-cap FTSE 250 was roughly flat by 0711 GMT as investors awaited U.S. retail sales data and more corporate earnings reports to assess the health of the world's largest economy. Luxury brand Burberry rose 6.5% to a near one-year high after it posted a stronger-than-expected rise in first-quarter comparable-store sales and affirmed its annual forecast.

A.G.Barr tumbled more than 23% on the mid-cap index after a challenging start to the year led the Irn-Bru maker to warn that its annual profit would sink 20% compared with last year.