* Unions disrupt public transport, some public services
* PM Samaras to meet coalition partners Monday over ERT
Greek Prime Minister Antonis Samaras moved to defuse a political crisis over the government's abrupt closure of state broadcaster ERT as trade unions staged a 24-hour strike on Thursday in protest at what was officially called a cost-cutting measure.
Samaras, who has branded defenders of ERT hypocrites, invited two left-wing junior coalition parties opposed to the shutdown to talks next Monday, his office said, seeking to avert political instability in the bailed-out euro zone country.
A senior government official said the conservative prime minister was open to discussing their proposals and a compromise was likely, though he did not intend to back down from closing and relaunching ERT as a smaller, more efficient entity.
"I believe there is scope for compromise and we will not go to new elections," the official told Reuters.
But the public clash between Samaras, who has vowed to transform Greece from "a real Jurassic Park" into a modern economy, and his partners raised doubts about whether a face-saving formula can be found.
"The country is on a knife's edge," a coalition source said.
The conflict with the Socialist PASOK and the Democratic Left parties, which want Samaras to reverse the shutdown, has rapidly turned into the most serious political crisis since the coalition came to power in June last year.
"Either there's a solution in a week or it's elections," conservative newspaper Kathimerini said on its front page.
Greek bond yields have crept back above 10 percent on fears of political instability and the government's failure on Monday to privatise natural gas DEPA.
About 2,600 employees are to lose their jobs at ERT, helping Athens meet a target for public sector firings under its bailout programme. Senior euro zone officials meet later on Thursday to discuss unlocking the next 3.3 billion euros of loans.
A senior government official said Athens was under pressure to show visiting EU and IMF inspectors that it had a plan to fire 2,000 state workers as required, and the ERT shutdown was the only option available to meet the goal.
The government described its decision to shut the 75-year-old broadcaster as a temporary measure pending the relaunch of a slimmed-down station within months.
Greece's two biggest labour unions staged a 24-hour strike against the ERT shutdown on Thursday, describing the ERT shutdown as a "coup-like move... to gag unbiased information".
City buses did not run in Athens and state-run train operator OSE stopped services across the country.
Over 10,000 protesters gathered outside ERT's headquarters, where workers have held a vigil since the closure was announced, waving flags and holding banners reading "Fire Samaras, not ERT workers!"
"Samaras can't tell us what to watch or not. This isn't about ERT or about its workers any more, it's about democracy and freedom of speech," said Thanos Lykourias, 30, an office worker, who earns 800 euros a month and lives with his mother.
An indefinite strike by the Athens journalists' trade union prevented some newspapers appearing and forcing commercial broadcasters to air reruns of sitcoms and soap operas instead of the news.
But there was little sign of private sector workers joining the stoppage. City streets were full of car traffic, supermarkets were open for business and cafes were bustling.
"The lowest ERT employee makes in a day what I make in a week, so why should I strike for them?" said vegetable vendor Yannis Papailias.
"Hundreds of thousands of people have lost their jobs. Who protested for them?" asked waitress Maria Skylakou as she served coffee to customers.
Data released on Thursday showed unemployment climbed to 27.4 percent in the first quarter of 2013 after more than 850,000 jobs, most in the private sector, were wiped out since the beginning of Greece's six-year recession.
Representing about 2.5 million workers, the unions have held strikes repeatedly since Europe's debt crisis erupted in 2010, although recent action has been less frequent and more muted than last year when marches frequently turned violent.
LIFELINE TO ISLANDS
The Hellenic Broadcasting Corporation ERT has shed viewers with the rise of commercial television, and its three statewide TV channels had a combined audience share of only 13 percent.
It is financed with about 300 million euros of mandatory fees raised through electricity bills, regardless of whether the household has a television set or not. In this far-flung nation, ERT is the sole broadcasting lifeline for residents of remote islands.
Many Greeks regard it as a wasteful source of patronage jobs for political parties. But the abruptness with which the government pulled the plug - blacking out screens with newscasters cut off in mid-sentence - was a shock.
"This is a fascist government, it doesn't care about workers that it dumps on the street," said George Papadopoulos, 32, an unemployed man who lives with his parents.
The hard left opposition has seized on the issue to attack the government. Leftist leader Alexis Tsipras, addressing protesting ERT workers in the second biggest city, Thessaloniki, on Wednesday, called on Greeks to defend democracy.
"What we experienced yesterday was unprecedented, not only for Greece but for all of Europe," Tsipras said. "Public television goes dark only in two circumstances: when a country is occupied by foreign forces or when there is a coup."