LISBON, Portugal — European Union leaders endorsed a reform treaty today to replace their failed European constitution and give the 27-nation union a more influential say in world affairs, diplomats said.

The new treaty will take effect in 2009 if it passes national parliamentary votes and referendums.

"With this new treaty, Europe has overcome an impasse that lasted for several years," said Portuguese Prime Minister Jose Socrates, who hosted the EU summit.

"Europe has emerged stronger from this summit, stronger to face global issues, stronger to take its role in the world and also to increase confidence in our economy and in our citizens," he told reporters.

The pact aims to achieve the same thing as the constitution that collapsed in 2005 when it was rejected in French and Dutch referendums: to expand the union's global influence by translating its economic might into a bigger diplomatic punch.

It will do so through quicker decision-making, more majority voting, more powers for the EU and give the bloc more power to act on global issues such as defense, energy security, climate change and migration.

Agreement on the treaty came after the EU leaders overcame last-minute reservations on minor points by, notably, Poland and Italy.

Italy won an extra European Parliament seat, while Poland held out for a complex voting formula making it tougher for large EU nations to outvote smaller ones.

"Basically Poland got what it wanted," Polish President Lech Kaczynski said. "The whole operation of the EU Reform Treaty is now crowned with success."

While it lacks the constitution's most contentious elements — such as EU flag and anthem — it will give its foreign and security affairs chief a seat on the EU Executive Commission with control over the EU's multibillion-dollar aid budget and its extensive network of diplomats and civil servants.

There will also be a smaller, more efficient EU executive and an EU president — chosen by the EU leaders for five-year terms — to "facilitate consensus" and represent the union abroad. In the future an exit clause will make it possible for nations to leave the EU.

European Commission President Jose Manuel Barroso said he will work hard to explain the benefits of the EU treaty to an often skeptical European public.

"Our citizens want to see ... what Europe brings them in benefits to their daily lives," he said.

On the Net: