By Deborah Haynes and Peter Graff LONDON, Feb 21 (Reuters) - Prime Minister Tony Blair looked set on Wednesday to outline a timetable for British troops to start withdrawing from Iraq, with media reports saying 3,000 soldiers could be home by the end of the year. Blair will tell parliament the gradual draw down comes as Iraqi forces take over more control of security in the south of the country, according to British newspapers and news channels. A spokesman at the prime minister's Downing Street office declined to comment on the reports, but said parliament would be updated first on any announcement about Iraq. Confirmation of a pull-out plan would be symbolic for Blair, who is due to leave office later this year. His decision to back the U.S.-led invasion of Iraq four years ago was hugely unpopular and has blighted the final years of his premiership. Media reports said Blair would tell parliament 1,500 soldiers would leave Iraq by the summer. The Sun tabloid said the first batch would be home in April. A further 1,500 troops could be out by the end of the year, BBC News, the Sun and the Times newspaper reported. Britain has 7,100 troops in southern Iraq. The Financial Times said Blair would first cut troop levels by 1,600, while the Guardian newspaper put the figure at 1,000, with all troops exiting by the end of 2008. Blair was expected to say the withdrawal reflected Britain's success in southern Iraq, according to the media reports. U.S. President George W. Bush, who spoke to Blair on Tuesday, appeared upbeat about a British pull-out and said he hoped U.S. forces could follow suit when conditions allowed. "President Bush sees this as a sign of success and what is possible for us once we help the Iraqis deal with the sectarian violence in Baghdad," Gordon Johndroe, spokesman for the White House National Security Council, said. A reduction in British numbers would come after Bush decided to send an additional 21,500 U.S. troops to Iraq to enhance security in Baghdad and restive Anbar province. BASRA SECURITY TRANSFER Britain has not yet formally announced cutbacks to its force, but Defence Secretary Des Browne has said he hopes to bring thousands of troops home by the end of this year. In a sign of Iraq taking a greater responsibility for security, Britain put Iraqis in command of the main Iraqi army unit in Basra on Tuesday. "The transfer is a significant step towards Iraqi forces taking responsibility for security in the city," the British military said in a statement. Blair said on Sunday Britain would cut its force once Iraqis were responsible for security in Basra, Iraq's second-largest city. He has said he will update parliament about the British mission in Iraq at the close of a four-month security operation in Basra -- Operation Sinbad -- which ended last week. Since the 2003 invasion that toppled Saddam Hussein, British troops have been responsible for Iraq's southernmost four provinces, which are mainly Shi'ite and have been quieter than mixed or mainly Sunni areas patrolled by Americans. The British handed over security responsibility for two of their four provinces to Iraqis last year and abandoned their main base in a third. The force is now concentrated in Basra and at a nearby air base. Commanders say they hope to withdraw from the city and keep a reserve force on standby at the base.
