Guinness may stop brewing its famous stout at St James's Gate in Dublin after more than 240 years. The company, now part of the Diageo group, confirmed yesterday that it was reviewing all its brewing operations in Ireland including the Dublin brewery.

"We have ruled nothing out," said Pat Barry, a spokesman for Guinness Ireland yesterday when asked about the future of the Dublin brewery. Guinness has four other breweries here, two in Dundalk and one each in Kilkenny and Waterford. The consolidation of the global brewing industry has meant that Guinness, along with most other producers, now had surplus production capacity.

"To remain competitive by world standards, there is an important need for Guinness to examine its current and future capacity requirements, and to consider how these can be met at significantly reduced cost," he said. The company, which employs 3,000 people here, has already announced plans to shed 100 jobs in its sales and marketing department. Guinness has invested more than £200 million (€255 million) in its Dublin brewing plant in recent years, but it suffers from being located in Dublin's increasing congested city centre. The site would worth millions on the open market as development land.

Arthur Guinness, the founder of the brewing dynasty, bought the St James's Gate brewery in 1759.

By the end of the century the brewery had been given over entirely to the brewing of stout.

During the next 100 years it grew to be the biggest brewery in the world and was the first to go public.

The company is also looking at rationalising its packaging plants in Dublin and at Runcorn, in Lancashire. Unions sources were speculating that the company's Dundalk plants are the ones most at risk. The Harp brewery in the town makes Harp larger, and Carlsberg, under licence from the Danish group. Guinness also owns Macardle Moore which makes the eponymous dark ale in the town.

In Kilkenny, the company has the Smithwicks brewery. It is understood the company has made the Government aware of the review process and has indicated that the brewing of some products may be relocated with the consequential closure of some plants. The company said yesterday that the review process should be completed later in the summer. "Our employees are well aware that this work is underway and we have committed to be as open with them as we possibly can, sharing the facts as soon as we have them," the spokesman said.