LONDON, United Kingdom — Burberry Group Plc, the U.K.'s largest luxury-goods maker, reiterated its forecasts for the year after sales of its spring-summer collection lifted first- quarter retail revenue more than analysts estimated.

Retail revenue advanced 21 percent to 339 million pounds ($504.7 million) in the three months ended June 30, London-based Burberry said today. Analysts predicted 316 million pounds based on the median of nine estimates compiled by Bloomberg News. Excluding currency shifts, revenue gained 18 percent, while same-store sales increased 13 percent. Analysts had expected a 5 percent boost to same-store revenue.

Burberry is widening its retail distribution and expanding its offer beyond apparel to target demand for its brand in buoyant economies such as Asia. The maker of $2,795 raincoats, which began operating its own fragrance and beauty division in April, expects new stores to boost retail revenue by a low-to- mid single-digit percentage in fiscal 2014, it said today, repeating a May forecast.

"Spring/summer 2013 was a standout season," Burberry Chief Executive Officer Angela Ahrendts said in the statement. "The macro outlook remains uncertain and we will continue to focus our investment on profitable high-growth opportunities by channel, region and product categories."

Global luxury sales will rise 4 percent to 5 percent this year, excluding currency shifts, Bain & Co. estimated in May. Growth will be sustained as booming demand in southeast Asia offsets a slowdown in China and Europe, according to the consultant.

By: Andrew Roberts; Editors: Celeste Perri, Thomas Mulier