The Premier League leaders reportedly wanted to expand the Old Trafford capacity to over 90,000, but plans have been shelved due to excessive cost.
The Glazer family, who own the Manchester club, are keen to maximise revenue, and an expansion of Old Trafford, which is already the largest Premier League ground, is believed to have been considered.
An extra 15,000 seats would have taken Manchester United's stadium into the upper echelons of the world's biggest grounds. It is currently the ninth biggest in Europe, the planned expansion would have taken it past Wembley Stadium as the second largest. Only the Camp Nou in Barcelona would have been bigger on the continent.
The report claims United were exploring the plausibility of expanding the South stand across a railway line which forms a border to the back of the stadium.
But, adding an extra tier would reportedly cost around £30m, and in the current financial climate, such a large construction project was deemed too costly.
On the pitch it was good news for United as they extended their lead at the top of the table this weekend, beating title rivals Manchester City 3-2 at the Etihad Stadium.
Sir Alex Ferguson's side also secured their passage into the last-16 of the Champions League, but the report suggests the club have experienced a reduction in the number of fans coming through the turnstiles this season.