Angry workers from Greek utility Public Power Corp. disrupted a shareholder meeting intended to launch the sale of a minority stake in its subsidiary power grid ADMIE, a Reuters witness said.
Between 40 and 50 members of staff unfurled a huge banner behind the podium of the general meeting which read "PPC is not for sale, it is not to be broken up."
Chairman Manolis Panagiotakis postponed the meeting from Thursday until July 11.
"We fear that by spinning off ADMIE some 5,000 jobs will be lost," said Giorgos Adamidis, head of the PPC workers union. "We will be back."
Thursday's incident is symptomatic of fierce workers' resistance to privatisations in Greece, which have frequently been put on the back burner because of staff objections or government reluctance.
They are however a key element of a third international bailout Greece signed up to last summer, worth up to 86 billion euros.
At Thursday's meeting, the utility had planned to start the process to sell part of the ADMIE grid.
PPC controls almost 95 percent of the Greek retail market. A sale of a stake in the grid is also part of a creditor-mandated drive to cut PPC's dominance of the local retail market.
Under bailout terms, Greece is obliged to sell up to 24 percent of ADMIE, now fully owned by PPC.
Earlier this month the country's energy minister was quoted as saying authorities had been approached by three parties interested in acquiring a minority stake in ADMIE, a grid of more than 11,000 kilometres of high-voltage power cables.