"We're not a club that sells its main assets, to service our debts we need to have a very successful team on the pitch and you don't achieve that by selling Cristiano Ronaldo.
"We're keeping him. We've no intention of letting him go and will make sure he's happy. He's going nowhere."
United's accounts show they have debts of £764m, but Gill said there were no doubts about the club's ability to manage and repay them.
"There are provisions in Uefa licences that deal with clubs being able to meet their obligations, you have to give forward-looking accounts for coming years to show you can meet them, which is quite right," he said.
"Look at the debt in isolation and, yes, it's a concern, but look at our income generation. Our revenue is well over £200m.
"Banks wouldn't loan those sums unless they were fairly confident they'd get their money back and if we didn't have a business plan which showed they'd get it back," he said.
"In Manchester United, we have one of the best clubs in the world and we have a significant amount of income which can service those debts, so let's not just look at one side (of the equation)."
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