Portugal opposition Socialists choose mayor of Lisbon as candidate for PM in next year's election

Lisbon mayor Antonio Costa waves to his supporters as he celebrates his victory in the Portuguese Socialist Party (PS) prime ministerial primary at his campaign headquarters in Lisbon September 28, 2014. REUTERS/Hugo Correia

LISBON (Reuters) - Portugal's main opposition Socialists chose the mayor of Lisbon, Antonio Costa, on Sunday as its candidate to be prime minister in next year's election, hoping to breathe new life into the party's drive to regain power.

In a ballot to select the party's prime ministerial candidate, Costa, 53, easily defeated party leader Antonio Jose Seguro, 52, who announced his resignation after the result.