United chief executive David Gill, who now reports to new owner Malcolm Glazer, said the fall in profits was largely down to reduced television money.
The club will officially announce the financial results today (Monday).
Despite United going out of the Champions League in the group stages this season, Gill remains confident the club will report good figures for next year's results.
But he refused to predict profits would exceed £50million for 2006, when the club will need to find a new shirt sponsor after Vodafone decided it would pull out at the end of this season.
The new stadium expansion means there will be nearly 8,000 extra seats from the start of next season, and Gill insisted the outlook for 2007 was "very positive".
