British supermarket Asda's Q2 like-for-like sales up 0.5 pct

(Repeats to additional subscribers)

LONDON, Aug 14 (Reuters) - Supermarket Asda, the British arm of the world's biggest retailer Wal-Mart, posted a 0.5 percent rise in second-quarter underlying sales in a tough grocery market seeing its slowest growth in a decade.

Asda, which trails market leader Tesco (Xetra: 852647 - news) , by annual sales and is vying with Sainsbury's to be Britain's No. 2 grocer, said on Thursday sales at stores open over a year, excluding fuel and VAT sales tax, rose 0.5 percent in the 10 weeks to June 30, versus the same period last year.

The outcome is an improvement on its first quarter performance when like-for-like sales rose 0.1 percent. (Reporting by James Davey, Editing by Paul Sandle)