Shares in Britain's Royal Mail should have been sold at a higher price when the firm was privatised last year, but the lost revenue was lower than previous estimates, a government-commissioned report concluded.
Lord Myners, a former Labour minister commissioned to see if the government could improve the way it sells public assets, said Royal Mail could have raised up to £180m more for the public purse.
The high profile public offering of a 60% stake in Royal Mail was trumpeted as a success by the Conservative-Liberal Democrat coalition, but it has drawn fierce criticism from the opposition Labour party and trade unions.
Critics argue the sale, which raised £2 billion, was rushed and point to a sharp rise in the share price after the sale as evidence of a botched deal. Business Secretary Vince Cable had insisted it would take time for a true share price to emerge.
Myners said his panel believed the offer could have beenincreased by 20p to 30p per share, equivalent to an additional £120m to £180m for the government.
"For the avoidance of doubt, we do not believe that a price anywhere near the levels seen in the after market could have been achieved at listing," the report said.
Royal Mail shares were issued at 330p in October 2013, and subsequently rose to reach almost double that level at 618p in January. The shares have since fallen back and are trading just under 400p.
A previous report on the sale by the public spending watchdog in April said the government had been too cautious in pricing the deal, leading to missed revenue of at least £750m.
Myners said in future the government should consider revising the book building process, in which large institutional investors express demand for the shares.