LONDON (Reuters) - Some hedge funds that bet against a series of Greek and Italian companies are nursing losses after the European Union's breakthrough plan for a 750 billion euro recovery fund sent stock markets surging across southern Europe. The funds, which include Citadel, Marshall Wace and AKO Capital, still hold short positions on companies such as Italy's Banco BPM and Greece's Piraeus Bank ahead of a June 18-19 EU summit to debate the recovery fund, aimed at helping European economies recover from the impact of the coronavirus pandemic.