Carlsberg and Heineken, the brewers preparing to make a joint formal offer for Scottish & Newcastle, have reportedly run into due diligence problems.

The brewers have found that some of their assumptions on how S&N allocated its profits between its different regions were incorrect, according to the Financial Times.

S&N splits its profits reporting into the UK, continental western Europe and the US, Russia and Asia, but does not give a lot of detail of where it makes money in each region, the paper claims.

Lehman Brothers, the investment bank arranging financing for Carlsberg, is also understood to have concerns about how it will refinance a bridge loan following sharp declines in the equity markets.