Tue May 21, 2013 2:28pm EDT
* Binding bids for DEPA due May 29
* Sintez, SOCAR to bid for DEPA's gas grid unit DESFA (Adds meeting between Gazprom chief and Greek Prime Minister)
By Harry Papachristou
ATHENS, May 21 (Reuters) - Gazprom is squeezing Athens for better terms to buy DEPA, Greece's sole retail gas distributor, a Greek official said, as the Russian gas export monopoly leverages its position as the only major player in the running.