TNT has admitted it is continuing talks with the government about buying a stake in the Royal Mail.
According to newspaper speculation, both TNT and private equity group CVC Partners have offered less than £2bn for a 30% stake in the state-owned organisation – below the government's original valuation.
The Postal Services Bill, which proposes part-privatisation of the Royal Mail in an effort to improve the way it is run and secure fresh investment, is being debated this month in the Commons.
Ernst Moeksis, a TNT spokesman, says: "We are continuing talks with the government about our interest in the Royal Mail. These are confidential discussions, but we have consistently expressed our interest."
CVC was unavailable 
for comment.