LONDON — Shares in newly-privatized Royal Mail soared on their stock market debut Friday, bolstering criticism that the company — which traces its five-century history to King Henry VIII — was undervalued by the British government.
The shares were up 31 percent to $6.91 by midday, a hefty gain for shareholders who got them at $5.27. Nearly 150 million shares, or 15 percent of the total issue, changed hands.
‘‘One can only say that investors have clearly given their stamp of approval to the offering,’’ said Brenda Kelly, senior market strategist at IG.
But the opposition Labour Party argues that the gains prove the government shortchanged taxpayers and could have gotten more than the 1.72 billion pounds ($2.75 billion) it received from the sale. Full story for BostonGlobe.com subscribers.