Greece's leftist Syriza party will seek to form a government with the Independent Greeks, its former coalition partner, a Syriza source said on Sunday after early national election results put the party in the lead. Official results showed that with more than 30 percent of Sunday's votes counted, Syriza were on 35.3 percent, against 28.15 percent for rivals New Democracy. Based on that calculation, Syriza would gain 144 seats in the 300-member parliament, and New Democracy 75.