British luxury brand Burberry warned on Wednesday that a fall in sales in the key market of Hong Kong in the last quarter of 2014 could impact its full-year margin.

Protests began choking parts of the Asian financial centre in late September, disrupting business in one of the world's top markets for luxury companies, which accounts for about $9.7 billion of global luxury sales, or 4 percent of the total, according to estimates by Bernstein Research.

Known for its raincoats with camel, red and black-check patterned linings, Burberry said retail sales rose 14 percent to 604 million pounds ($916 million) in its October-December third quarter, with comparable growth of 8 percent, steady on the previous quarter.

Burberry said Asia-Pacific delivered low single-digit growth compared to double-digit growth in the previous six months, as sales in the high-margin market of Hong Kong fell slightly even though the Chinese mainland and South Korea grew by a mid-to-high single-digit.

Even before the protests, luxury goods companies had been under pressure from an anti-corruption campaign in China, which has sapped appetite for such goods among the mainland residents, some of Hong Kong's biggest tourist spenders.

Burberry said the slowdown in Hong Kong and a change in the regional sales mix had more than offset a modest improvement from exchange rate movements, which it said in November could hurt its full-year retail/wholesale margin.

It reiterated the rest of its outlook for the full year for its wholesale and licensing businesses, and added that it expects net new space to contribute about 5 percent to total retail revenue growth.