Greece's dominant electricity utility, Public Power Corporation SA (PPC.AT), extended rolling blackouts early Thursday as an ongoing strike by workers over pension reform dragged into a fourth day.

Greece's dominant electricity utility, Public Power Corporation SA (PPC.AT), extended rolling blackouts early Thursday as an ongoing strike by workers over pension reform dragged into a fourth day.

The power outages, lasting about 2 hours, began at 0600 GMT, and hit almost four dozen localities around the country, including districts around metropolitan Athens, the capital and largest city.

"Currently, the number of power plants out of operation and the shortfall in power generation is the same as yesterday," a PPC official said.

The strike by the power sector workers' union, Genop, has so far shut down 16 power plants. Combined with another three undergoing scheduled maintenance shutdowns, that has meant a total of 4.9 gigawatts generating capacity are out of operation.

Combined, that represents almost 40% PPC's total installed capacity of some 12.7 GW. PPC, the one-time monopoly, provides about 90% of Greece's electricity needs.

The power shortfall has also forced Greece's grid operator, the Hellenic Trasmission System Operator, or HTSO, to sharply increase electricity imports from neighboring countries to cover peak demand periods.

"We are importing more power from Italy, Bulgaria and the Former Yugoslav Republic of Macedonia," said Evangelos Lekatsas, president of HTSO.

He added that imports during peak morning and evening demand periods are now average 1.1 GW, compared with 600-700 megawatts normally.

Originally, the strike was scheduled to last four days, but Wednesday, Genop, decided to extend its strike action for another six days.

Since being reelected in September last year, the center-right New Democracy government has been pushing to reform Greece's pension system and will introduce long-awaited legislation this morning.

However, the reforms have engendered strong opposition from unions. Bank workers have also declared a 24-hour strike for Thursday, while a three day long strike by workers at the Bank of Greece, the country's central bank, has crippled the country's payments system.

Private sector umbrella union GSEE is also meeting Thursday to discuss further strikes in opposition to the reforms and has vowed to call a 24-hour nationwide general strike when the reforms are considered in parliament.