* To speed up sale of branches, current accounts, mortgages
* New CEO also launches strategic review on first day in job
* Businesses could be worth over 3 billion pounds
* Shares flat
(Adds analyst comments, details, updates shares)
By Sudip Kar-Gupta and Steve Slater
LONDON, March 1 (Reuters) - The new boss of Lloyds Banking Group began the forced sale of 600 retail branches on Tuesday, his first day in the hot seat, offering suitors a chance to create Britain's seventh biggest bank with one deal.
Antonio Horta-Osorio also launched a strategic review and said the part-nationalised bank will not announce further branch closures until the end of the year.
Lloyds was told by European authorities in November 2009 it had four years to sell at least 600 branches, 4.6 percent of the personal current (or checking) account market and 19 percent of its mortgage book to limit competition distortions after taking a taxpayer bailout.
The businesses for sale would on their own, create Britain's seventh biggest bank or building society in terms of current accounts and branches and could be worth over 3 billion pounds ($4.9 billion), analysts have said.
NBNK Investments, a new banking start-up, has said it wants to buy the Lloyds branches. Other suitors could include Virgin Money, National Australia Bank or Spain's BBVA.
PRE-EMPTIVE MOVE?
Lloyds, Britain's biggest retail bank since it took over troubled rival HBOS during the banking crisis, has decided to move ahead with the branch sales as Britain's Independent Commission on Banking investigates UK banking competition.
The ICB is due to report back to the government with its findings in September.
"There may be a desire to show progress with the EC mandated disposals before the report is published in September, it could be a tactical approach to that, or it may be a desire to get on with dealing with the requirements and bringing forward normality," said Ian Gordon, analyst at Exane BNP Paribas.
Lloyds has until November 2013 to sell the assets and the previous chief executive Eric Daniels said he wanted to complete the integration of HBOS before starting the sell-off. The bank said last month the HBOS integration was ahead of plan.
Portuguese-born Horta-Osorio previously ran Santander's UK operations.
Lloyds is expected to hold a beauty parade to pick advisers for the branch sale -- dubbed "Project Verde" -- in the next few weeks.
Assets on the block include Cheltenham & Gloucester mortgages, the TSB brand, branches of Lloyds TSB in Scotland and some in England, and Intelligent Finance.
The bank estimated the businesses to be sold contributed about 500 million pounds of pretax profit in 2008 and generated income of about 1.4 billion.
Lloyds is 41 percent owned by Britain after being bailed out during the credit crisis when it was saddled with billions of pounds of losses after the takeover of troubled rival HBOS in 2008, a controversial deal which was brokered by the Labour government of the time.
By 1045 GMT Lloyds shares were up 0.1 percent at 62.1 pence, valuing the bank at 42 billion pounds. ($1=0.6140 pounds) (Editing by Dan Lalor and Greg Mahlich)