The City is expecting a fall in brewer's SABMiller's American volumes later this month when it reveals poor trading in its key US market.
SABMiller, which is listed on the London Stock Exchange, is said to be losing volumes to rivals in the US, notably Budweiser owner Anheuser-Busch.
US drinks trade journal Beer Marketers Insights has reported that SABMiller's sales in Texas, its biggest market, have fallen by 14 per cent this year.
"I think the problems in the US are largely already in the share price," said Stuart Price, beverages analyst at WestLB.
"The underlying situation, according to my analysis, is that volumes in the US are down seven per cent."
The South Africa-based brewing giant acquired the US Miller business in a £3.5bn deal last year. Miller's sales had been declining for some time, and the new owners say it will take two to three years to reverse the trend.
However, some analysts have suggested that achieving success in the mature and highly competitive US market is a very different prospect from SABMiller's experience of building sales in developing markets.
Some pundits have said the share-price will suffer when SABMiller puts out figures later this month. "I think they will be okay as long as they can demonstrate that they are turning the corner," added Mr Price.
Meanwhile, SABMiller's newly-acquired Italian subsidiary, Peroni, has lost the contract to distribute Budweiser in the Italian market. Anheuser-Busch and Peroni have agreed to end their partnership in November, after SABMiller acquired a 60 per cent stake in the Italian brewer in May.
Peroni has held the rights since 1995, but from November will replace Bud in its portfolio with Miller Genuine Draft.
Anheuser-Busch has now signed a deal with Heineken's Italian subsidiary to take over distrubution of Budweiser. Andrew Day, vice president and managing director of Anheuser-Busch Europe, said: "Heineken will be an excellent partner for Anheuser-Busch in Italy, and we look forward to working with them to grow the Budweiser brand. Italy continues to be an important market for our company, and we're excited about this new partnership."