MILWAUKEE — The maker of Guinness is touting a new stout beer in the U.S., a maltier, fizzier version of its older, creamier sibling, the world's best-selling stout.

"This is more about refreshment and zing," said Guinness master brewer Fergal Murray, who created the new carbonated brew.

The limited-edition Guinness 250 Anniversary Stout celebrates Arthur Guinness' signing of a 9,000-year lease in 1759 at St. James's Gate Brewery in Dublin, still the company's flagship brewery.

When it arrives in U.S. bars and stores April 24, the anniversary brew will be the first new stout that Guinness has exported to the U.S. since it brought over Guinness Draught in the mid 1960s.

Guinness Draught, first brewed after Arthur Guinness decided to stop making ales and start making porters in 1779, became synonymous with Ireland over the centuries.

More than 1.8 billion pints are consumed in 150 countries each year.

The anniversary stout will be available only in the United States, Australia and Singapore, according to Diageo PLC, owner of Guinness and the world's largest liquor producer.

The company's other brands include Johnnie Walker and Baileys.

The beer is expected to be available for about six months, said Patrick Hughes, brand director for Diageo Guinness USA.

A big marketing campaign, complete with advertisements and promotions at bars, launches late this month.

"The brand is one of sort of strength, staying power and authenticity," Hughes said. "We think consumers are really going for brands with that strength and trusted authenticity."

They also want something new to taste, which this new beer delivers with carbonation, two types of malt and triple hops, Murray said.

The anniversary stout uses carbonation, rather than the combination of nitrogen and carbon dioxide used by Guinness Draught. The result? More zing.

The taste is different, too, although it retains the deep flavor of Guinness Draught.

Guinness 250 Anniversary Stout also has more alcohol, at about 5 percent by volume, compared with 4.2 percent for Guinness Draught.

Pouring will be simpler, too. This anniversary stout is poured only one way, at an angle, in contrast to Guinness Draught's famous two-part process, which involves filling the glass about three-fourths of the way at an angle, letting the surge of foam settle, then pouring the rest.

The anniversary comes in a rocky year for Diageo. As the global recession deepens and consumer confidence remains low, the London-based company has been cutting costs and shedding jobs to protect its profits.

In January, it said it may change or abandon $1.1 billion plans to upgrade production in Ireland and open a new state-of-the-art brewery.

Guinness accounts for about 70 percent of the stout volume in the U.S., dominating a category that makes up less than 1 percent of total U.S. beer volume, according to research firm Nielsen Co.