United failed to reach their target of season ticket sales this summer, the club's chief executive David Gill has confirmed.
But Gill insisted the figure is still "pretty good" in the current economic climate and that the club is in good financial shape.
Gill said the number of season tickets sold was 51,800 compared to the target of 54,000, and that executive seat sales were "on track".
United's season ticket sales have been conducted against a backdrop of a campaign by fans' group the Manchester United Supporters' Trust (MUST) urging a boycott in the hope of persuading the American owners, the Glazer family, to sell the club.
Asked about the season-ticket protest, Gill told Press Association Sport: "I'll be clear on that. Last year our target was 54,000 season tickets, we've sold 51,800, which is pretty good in the current climate.
"We've sold more season tickets than the capacity of most Premier League grounds. Our executive seat sales are on track as compared with last year in a different market.
"I think the bare facts are that the club is in good financial shape. The ticket sales have held up. We sold out for Newcastle and West Ham but we are not complacent and we've got to keep working to make sure that we fill the ground for every game and we'll do that by playing great football, attractive football, exciting football that brings fans in."
The protest against United's owners surrounds the debts they took on to buy the club. These now stand at more than £700million - including a £500million bond scheme, and £202million in payment in kind (PIK) loans.
BBC's Panorama claimed earlier this summer the Glazers' shopping mall empire in America was facing problems but Gill would not be drawn on that, stating instead the club was very successful financially and were comfortable with the position.
Gill added: "I'm not going to comment on that [Panorama]. We've had another very successful year off the pitch when we announced our results for June 2010 they were excellent, generating cash.
Shortfall
"We have put in place a long-term financial structure for the club with the bond, obviously that's serviced on a regular basis.
"So no I don't think it impacts us at all. So I think we've got to be comfortable."
Duncan Drasdo, the chief executive of MUST, said the season ticket shortfall was "a tipping point" in the Glazers' ownership. He pointed out that other clubs had sold out despite the slump.
Drasdo said: "We have clearly reached a tipping point in the Glazers' ownership. Up until this season they increased ticket prices aggressively every year and could get away with it because the loyal fans they forced out were replaced by others still prepared to pay the increased price.
"However this season, despite a ticket price freeze and an unprecedented marketing campaign, there are still thousands of season tickets and hospitality packages unsold.
"The failure to sell out season tickets is very significant as the Glazers depend on an excess of demand over supply to exert control over supporters."
Drasdo insisted part of the failure to sell out was due to fan dissatisfaction.
He added: "Other clubs have sold out under the same economic conditions so clearly other factors have come into play.
"There is huge dissatisfaction with the way the Glazers have exploited the supporters and the football club and thousands of season ticket holders chose not to renew for that reason while others are simply unhappy at the lack of investment in the squad while the owners continue to take millions out of the club.
"No wonder the Glazers are loved by Manchester City fans as much as they are disliked by United supporters. The sooner we are released from the millstone of their ownership the better."
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