Greek Prime Minister Antonis Samaras has announced his new cabinet, which is dominated by MPs from his conservative New Democracy party.
Vassilis Rapanos, the chairman of the National Bank of Greece, has been given the key post of finance minister.
The socialist Pasok and Democratic Left parties have two party officials in the cabinet, but have barred their MPs from taking part.
It is believed they may not want to be associated with austerity measures.
The BBC's Mark Lowen in Athens says the decision of New Democracy's coalition partners not to participate fully in the cabinet does not bode well for the effectiveness of the new government.
New finance minister Mr Rapanos, 65, is a former economics professor who served in the economy ministry when Greece joined the euro in 2001.
Some reports suggest he is seen as being close to Pasok.
New Democracy's deputy leader Dimitris Avramopoulos has taken the post of foreign minister in a smaller cabinet of 18 ministers.
The party won 129 seats in Greece's 300-seat parliament on Sunday, including a 50-seat bonus for coming first in the election.
Along with Pasok and Democratic Left, the new government will have a majority of 29.
Mr Samaras became Greece's fourth prime minister in eight months at a brief ceremony at the presidential palace in Athens on Wednesday.
German Chancellor Angela Merkel has reportedly congratulated Mr Samaras in a letter, saying she looks forward to co-operating with him.
"You're taking over the country at a difficult time," she wrote, as quoted by Greece's Skai TV. "We all have expectations of your government."
People in Athens who spoke to Reuters news agency were doubtful the new government could improve the Greek situation.
"I don't have anything against [Samaras] but I believe that all the old politicians, like Venizelos and Samaras, should leave and something different should happen so we can have someone new," said Danae, a 46-year-old kindergarten teacher.
"Otherwise, I don't think anything will happen."
Bailout 'off track'
Greece will be represented at a eurozone finance ministers meeting in Luxembourg by the outgoing Greek Finance Minister George Zanias.
Mr Rapanos is not expected to be sworn in until Saturday.
A top bailout official has warned eurozone states that they must tell Greece to make fresh budget cuts or raise more taxes, or face having to pay themselves.
The country got an initial EU-IMF package worth 110bn euros (£89bn; $138bn) in 2010, then a follow-up this year worth 130bn euros.
It has also had 107bn euros of debt, held by private investors, written off.
Greece's second bailout is "totally off track, months behind schedule", Thomas Wieser, head of the key Euro Working Group, told AFP.
Either you "stick to the fiscal targets and then you need additional measures" from Greece, he said, or you change deadlines, in which case "you need extra money".