SOFIA, Bulgaria—Bulgaria’s center-right GERB party on Friday became the second political party to give up trying to form a new government since last month’s inconclusive parliamentary poll, bringing the Balkan country closer to a third election this year. President Rumen Radev had asked GERB, the party of former long-serving premier Boyko Borissov, to try and lead the country after the anti-establishment There Is Such a People (ITN), which narrowly won the July 11 polls, abandoned efforts to form a minority government. But with just 63 seats in the 240-member parliament following the July election, just behind ITN’s 65, GERB is well short of a majority and other parties have refused to cooperate with it due to public anger over entrenched corruption in the European Union’s poorest member state. Before returning the mandate to Radev, GERB’s Prime Minister-designate Daniel Mitov, already in campaign mode, presented to reporters a potential list of cabinet …