THE chief executive of HSBC, Stuart Gulliver, has said the giant bank could decide within months to move its headquarters from the UK insisting the possibility of a change was not an idle threat.

"It's going to take us a few months not years," Mr Gulliver told reporters regarding the timescale for deciding whether to shift the bank's HQ to another country.

He added: "This isn't meant to be a threat. This is just very objectively looking at a few facts."

HSBC's Glaswegian chairman Douglas Flint told last month's general meeting that the bank had launched a formal review of where it should have its headquarters.

Some institutional shareholders are said to have been urging HSBC to consider moving back to its former Hong Kong home.

HSBC launched the review amid concern about the Tories' intended referendum on the EU and the prospect of a continuing squeeze on banks in the UK.

George Osborne increased the levy on banks, to 0.21 per cent of their total debts, from 0.156 per cent, in The Budget.

Regarding increases in the levy, Mr Gulliver said: "That's actually going to make it impossible for us to stick to our commitment to make the dividend progressive."

HSBC is expected to pay $1.5 billion (£1bn), or about seven percent of expected profits, under this year's bank levy.

Mr Gulliver said HSBC had announced the HQ review shortly before a general election to raise the political profile of the issue.

However, the bank would have to get shareholder approval for a headquarters move.

Mr Flint told last month's general meeting the question is a complex one.

HSBC will hold an investor update on June 9. Mr Gulliver said it would give more detail about the HQ review on the day but did not expect to have completed it by then.

The group increased first quarter pre-tax profits by four per cent annually to $7.1bn compared with analysts' forecasts of around $5.8bn.

Growth in investment banking profits compensated for increased compliance and regulation costs.

HSBC began life in Hong Kong 150 years ago. It moved from Hong Kong to London in 1993 when it bought Midland Bank.