(Adds British pledge, context)
BRUSSELS, Sept 16 (Reuters) - The European Union pledged an additional 650 million euros ($862 million) in aid for Somalia on Monday to back a three-year reconstruction plan aimed at building on fragile security gains in the country.
European Commission President Jose Manuel Barroso made the pledge as Somalia's government and international donors met in Brussels to sign up to a plan designed to bolster security and build an inclusive political system.
EU officials hope international donors at Monday's meeting will pledge more than a billion euros in total to back the plan.
"Today I am proud to pledge an additional 650 million euros to support this new phase in the life of Somalia," Barroso told reporters, saying this was on top of 1.2 billion euros provided by the EU since 2008.
Britain separately announced a new 50 million pound ($79.33 million) aid package for Somalia.
Somalia plunged into two decades of civil war and lawlessness after the overthrow of President Siad Barre in 1991.
But donors have seen signs of stabilisation since the African Union's peacekeeping troops helped drive Islamist al Shabaab rebels out of Mogadishu and many other strongholds in central and southern Somalia. ($1 = 0.6303 British pounds) (Reporting by Adrian Croft; Editing by Justyna Pawlak and Alison Williams)