Banking giant HSBC is reportedly set to announce plans to keep its headquarters in the UK after a high profile lengthy review. 

It is understood the decision could come as soon as this week, ahead of its annual results on February 22. 

A decision to keep its London HQ comes after Chancellor George Osborne has made a series of concessions to the City in recent months. 

HSBC's review was announced in April last year by chairman Douglas Flint at the bank's annual meeting. 

It cited increasingly onerous British regulatory conditions and the UK bank levy introduced in 2010 - a tax based on the size of any UK-based banks' global balance sheet. 

HSBC, which has much of its business based in Asia, said the levy cost the bank $1.1 billion (£720m) in 2014. 

The bank has also had to ringfence its UK retail bank, to protect customers and business clients from more risky investment divisions. 

The head office of HSBC's UK retail bank is being relocated from London to Birmingham by 2019 amid the new rules and HSBC is said to be considering a sale of the business, which was known as the Midland before being swallowed up by it in 1992.

HSBC has 48,000 of its 257,000 staff in the UK. 

During its review, the bank reportedly looked at bases in Hong Kong, Singapore, the US and Frankfurt. 

But since then, Mr Osborne said in last July's Budget he would gradually reduce the bank levy over the coming years. 

Last year Mr Osborne also called for a "new settlement" to end banker bashing and was widely reported to have ousted tough-minded Martin Wheatley, head of City watchdog the Financial Conduct Authority (FCA) in July, raising concerns about political influence at the regulator. 

It was announced last month that Bank of England deputy governor Andrew Bailey will replace him as chief executive of the FCA. 

At the end of December the FCA dropped its probe into banking culture, set up in the wake of the billions banks paid out in fines over attempts to rig the Libor bank rate lending market. 

The Chancellor and the Bank of England were both forced to deny they played any part in that decision.