** The math behind HSBC returning its HQto the bank's roots in Hong Kong makes sense, says Bernsteinanalyst Chirantan Barua
** A move to HK would eliminate the need to pay more thanthree-quarters of that levy -- a potential boost to earnings ofalmost $1.4 bln, according to Bernstein. Costs associated withshifting domicile to HK not likely to be more than $1.5 bln,broker adds
** HSBC paid a UK bank levy of $1.1 bln last year, and thislevy could rise to $1.8 bln to as much as $2.2 bln if a Labourgovt is elected in the UK in two weeks time, Barua says
** HSBC, Europe's largest lender, has ordered a review intowhether it should move its HQ out of Britain. The new wasgreeted by a 2.8 pct rise on its share price
** One caveat, according to Barua, is how accepting the HKMAwill be of HSBC's $2.5 trillion balance sheet but with capitallevels almost 50 pct more than pre-2007 levels should give themsome comfort
** ** HSBC and smaller rival Standard Chartered shifting HQs would leave the UK govt with a £1.8 bln hole todayand a nearly £1.7 bln hole under the Labour party's financialplans, Bernstein estimates (RM: vikram.subhedar.thomsonreuters.com@reuters.net)