LONDON -(Dow Jones)- U.K. retail stocks were slightly higher Thursday after surprisingly strong U.K. retail sales data boosted sentiment on a sector that has been under pressure for some months.

U.K. retail sales posted their biggest monthly gain for 22 years in May, The Office for National Statistics said Thursday. Sales rose 3.5% on the month and 8.1% on the year, compared with expectations of a monthly slide of 0.1% and a year-on-year gain of 4.1%.

While the figures were greeted with bemusement by some analysts due to low consumer confidence and a slew of negative trading updates from retailers in recent months, retail stocks reacted largely positively.

By 0900 GMT in London, shares in (TSCDY) - the U.K.'s largest retailer - grew 1.3% to 386 pence, with fellow supermarket ( JSAIY) up 0.2% at 326 pence. William Morrison Supermarkets PLC (LSE:MRW) (MRW.LN) shares were 1.1% lower at 268 pence.

The ONS said that the high retail sales levels were led by food stores - which had their largest monthly gain since January 1986. Sales of clothing and footwear also rose sharply, it said.

Shares in the country's largest clothing retailer by sales Marks & Spencer Group PLC (LSE:MKS) (MKSY) gained 1.9% to 348 pence, with shares in (ASBFY) - owner of the Primark clothing chain - gaining 1% to 804 pence. Next shares meanwhile recovered some of their earlier falls to trade down 0.6% at 991 pence.

Other large retailers to benefit from the strong figures were Home Retail Group PLC (LSE:HOME) (HOME.LN), up 0.4% at 212 pence and Debenhams PLC (LSE:DEB) (DEB.LN) - up 0.5% at 49 pence.

James Knightley, economist at ING in London described the retail sales figures as "very odd."

"We must all be very fat after spending an extra 3.3% in real terms on food last month," he said. "Because of the extra weight we have gained we have had to throw out all of our clothes and spend an extra 9.2% in real terms on clothing and footwear."

Some retailers had claimed that May was a better month for consumer spending after a wet March and April hit sales during those months. But recent store sales figures hadn't suggested such a surge in overall retail spending.

-By Michael Carolan, Dow Jones Newswires; 44-20-7842-9278; michael.carolan@ dowjones.com

(Jeannie Clarke contributed to this article.)

    (END) Dow Jones Newswires   06-19-08 0537   Copyright (c) 2008 Dow Jones & Company, Inc.