European shares climbed to a three-week high on Tuesday, extending the previous session's rally on expectations that Greece was getting closer to a debt deal, Reuters reported. Greece's ATG share index rose 4.2 percent, adding to a 9 percent surge in the previous session, while the country's benchmark banking index was up 7.3 percent. The Athens' ATG index remains down by around 5 percent since the start of 2015, due to Greece's ongoing debt problems, but it has recovered from a slump last week. The pan-European FTSEurofirst 300 index rose 1.1 percent while the euro zone's blue-chip Euro STOXX 50 index - which had risen 4.1 percent on Monday in its biggest one-day percentage gain since August 2012 - also climbed 1 percent.