Britain's finance ministry has mistakenly released potentially market-moving information and blamed a website error for erroneously saying it planned to sell £4bn of shares in Lloyds Banking Group.

The British government is not planning to sell the shares, and the release was "completely erroneous", a Treasury spokesman said.

"The Treasury is urgently looking into why this happened," he said.

People familiar with the matter said investors should not read anything into the release, which was received by news organisations, about any plans by the government to sell more of its stake in Lloyds soon.

Such information is highly market sensitive and if reported could have caused Lloyds shares to fall. 

Lloyds shares briefly dipped in the minutes following the email release at 1.59pm, but recovered to close up 0.4% at £77.75p.

Britain still owns a quarter of Lloyds, after selling two blocks of shares in the bank in September and March. The stake is held by UK Financial Investments (UKFI).

An email, headlined "Press release: UKFI announces its intention to dispose of approximately 7.5% of Lloyds Banking Group plc (test)", was sent to people who had signed up for automatic releases on the website, a site for government information.

The emails, triggered when a document was mistakenly uploaded to the website, carried a link to a statement on the site which said UKFI planned to sell 5.35 billion shares by a placing to institutional investors. 

The page was later deleted.

The headline and statement were in fact repeats of a press release sent out on 25 March but they had today’s date on them. The latest versions also had "(test)" on them.

Lloyds shares fell 4% on 26 March after Britain sold 5.6 billion shares, worth £4.2bn.

Under the terms of that sale, UKFI agreed not to sell anymore until 23 June, although such lock-up agreements can be waived.

The timing of the next government stake sale in Lloyds is under close scrutiny. The shares are above the level of the last sale and the government is expected to sell more shares this year, possibly including an offer to retail investors.

UKFI said it was not selling any Lloyds shares and the old Treasury press release was published in error "following routine website testing" on the website. 

"We are conducting an urgent review into how this happened to make sure this does not happen again," it added in a statement.

Lloyds declined to comment.