ATHENS (Reuters) - Greek centrists elected politician Fofi Gennimata on Sunday to lead a center-left party alliance, hoping to win back voters disillusioned after seven years of crisis and boost their popularity as the country emerges from bailouts. Past attempts by centrists to form parties and alliances have not fared well and the latest bid is seen as a last-ditch effort to restore unity and attract voters, many of whom defected to the ruling leftist Syriza party over the years of painful bailout reforms. The new alliance includes Greece s once-powerful Socialist PASOK party, which Gennimata already leads, the Democratic Socialist Movement, the Democratic Left and the To Potami party. Gennimata won about 58 percent of the vote.  PASOK ruled Greece for decades but has seen its popularity sliding to single-digit figures since 2010, when it signed up to Greece s first bailout from the EU and the International Monetary Fund in return for draconian austerity. It has 19 seats in the 300-member parliament. The centre-left Potami, which was founded in 2014 and first entered parliament with 6.1 percent in a 2015 national election  now ranks eighth in opinion polls with 1.5 percent. It has six MPs. Greece s leftist-led Syriza government was catapulted to power in January 2015 promising to end austerity. It was forced to sign up to a new rescue package, the country s third bailout a few months later. That bailout expires in August.  Prime Minister Alexis Tsipras  term ends in 2019 and he says he will seek a new four-year mandate then. But his ratings have been sagging in opinion polls behind the main opposition, the conservative New Democracy party.     