SCOTCH whisky distiller William Grant & Sons has revealed its annual turnover topped £1 billion for the first time last year, although profits dipped as it invested for the long term.

Sales of its Glenfiddich single malt, which family-owned William Grant noted was the biggest-selling in the world in its category, topped one million cases in 2011.

A case contains 12 bottles, a company spokesman noted.

William Grant, unveiling its 2011 results yesterday, said its turnover had risen by 9% last year to £1.05bn. It declared an operating profit of £126.3 million for 2011, down from £132.4m in 2010.

Highlighting the reason for the dip in profits, it said: "Whilst the tough global economic conditions made 2011 a challenging year, the company continued to strengthen its business by building the value of its core brands and investing in its innovation brands, employees and its infrastructure around the globe for the long term, explaining the slight dip in profits."

The distiller said sales of its Grant's blended Scotch whisky had grown to more than five million cases last year.

It added that growth in the value of sales had been ahead of the increase in volumes for both Glenfiddich and Grant's last year.

The rise in William Grant's turnover in 2011 was achieved in a year in which overall exports of Scotch whisky surged by 23% to a record £4.23bn.

Industry figures published earlier this week showed Scotch whisky exports in the first half of this year were down marginally on the record level achieved in the opening six months of 2011, as sales to Spain tumbled, but demand from the US continued to grow.

The figures, from the Scotch Whisky Association, showed exports in the six months to June 30 totalled £1.786bn, falling just £12m short of the £1.798bn figure for the first half of 2011.

William Grant's core brands also include Tullamore Dew Irish whiskey, which was acquired in 2010, Hendrick's Gin, The Balvenie single malt, and Sailor Jerry rum.

The distiller said it had continued to invest in its "innovation brands", including Hudson Baby Bourbon, Monkey Shoulder and Reyka vodka.

And it highlighted its acquisition of full ownership of its premium tequila brand, Milagro, which it said was performing well in its core markets of the US and Mexico.

The company spokesman said William Grant had, before moving to 100% ownership of Milagro, held a 75% stake, having raised it to this level previously from 50%.

Stella David, chief executive of William Grant, said: "Whilst 2011 saw some tough global economic conditions, the company performed well thanks to the continued success of our premium spirits brands and our consistent focus on building brand equity, improving our route to market and investing for the long term."

William Grant employs more than 2000 people around the world.

This workforce includes 1043 people in the UK, 824 of whom are in Scotland.

The distiller noted that Robert Polet, a former chief executive of luxury goods company Gucci Group, had joined its board as a non-executive director in September last year, and said this underlined its "continued focus on building a premium portfolio of spirits brands".

William Grant also established a marketing office for the Nordics last year, in the Swedish capital of Stockholm.