Stella Artois lost market share in the past six months as AB InBev shifted its promotional fire towards US favourite Budweiser.

The world’s largest brewer today said UK beer volumes – not including cider – had tumbled by 10.1% in the second quarter, and by 9.9% for the first half of the financial year.

The company blamed “unfavorable weather” as well as loss of market share for the dip in volumes. It said drinkers had switched from bottles to multi-pack cans at lower price points, hitting Stella Artois and Beck’s in particular.

Budweiser “delivered a solid performance and gained market share” over the period, the company said in its latest trading statement.

“These figures reflect a challenging UK market in the first half of the year, impacted by poor weather but also by record tax increases,” said UK president Inge Plochaet.

The performance comes after AB InBev cut the alcohol content of Stella from 5% abv to just 4.8% at the beginning of the year – a move industry figures speculated was designed to lower duty costs.

“Our volumes were also negatively impacted by competitive activity in the off-trade,” Plochaet added. “Nevertheless, Budweiser delivered a solid performance and gained market share in HY12, while Stella Artois Cidre was the number one premium cider in the off trade by volume and value sales.”

Group sales were up 5.4% for the first half of the year. Beer volumes were down 0.5% for the period, but non-beer volumes grew 4.2%.

EBITDA was up almost 5% to $7.146bn (£4.55bn).