Accounts for Manchester United's holding company Red Football Joint Ventures Limited showed the debt had risen by 17 million pounds in the year.
Net interest for the period was 68.5 million pounds.
The debt figure overshadowed the fact the company reported a profit of 6.4 million pounds for the financial year, compared to a loss in 2008 of 42.7 million pounds.
In 2009 United won the Premier League title for the third consecutive season, triumphed in the League Cup and lost the Champions League final to Barcelona.
The club's finances were also boosted during that time by the sale of Portugal winger Cristiano Ronaldo to Real Madrid for 80 million pounds.
Red Football said in the accounts its strategy for the future was to maintain the team's success on the pitch, boost the global brand and further develop its media rights.
United said earlier this month they would launch a 500 million pound high yield bond to help refinance the debt taken on by the American Glazer family to buy the club in 2005.
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