Mr Barroso, a conservative former prime minister of Portugal, made his announcement following talks with leaders of the Czech Republic and Sweden, the current and next holders of the EU presidency.
He has held the post since November 2004 and he is the only officially declared candidate so far.
'The President of the European Council has today asked me if he can put forward my name for a second mandate in view of the consultations that he will be making in preparation forthe next European Council. I have agreed to this request.'
Mr Barroso has long coveted a new mandate - his term expires in late October - but, leaving the door open should he be rejected, he vowed to take the job only if nations and the EU parliament endorsed his programme for the future.
The European Commission is the EU's unelected executive arm. It is guardian of the bloc's treaties, proposes legislation and polices competition issues, and will have an annual budget next year of €138bn.
Many countries want Mr Barroso's candidacy to be endorsed by EU leaders at a summit from 18 to 19 June in Brussels, but France and Germany would prefer his nomination to be announced only after the new Lisbon Treaty of reforms has been ratified.
French President Nicolas Sarkozy has had a mixed relationship with Mr Barroso, lavishing praise on his commission's work, then complaining loudly after the commission warned Paris over proposals to bail out its ailing auto industry.
In the same press conference, European Commission President, Jose Manuel Barroso, explained that he wants to give the Irish government what it needs to call a second referendum on the Lisbon Treaty and to give it the best chance to win.
