The 53-year-old Yanis Varoufakis was named to the post as Prime Minister Alexis Tsipras’ governing Syriza party announced a Cabinet that includes officials from its coalition ally, the anti-bailout and right-wing Independent Greeks.
Panos Kammenos, the Independent Greeks leader, was named defence minister.
Varoufakis has been a vocal critic of Greece’s bailout agreements, arguing that repayment of the country’s huge rescue package loans should be linked to growth, a policy change he argues would benefit eurozone lenders.
He has held teaching positions in Britain, Australia, Sweden, Greece and the United States.
Syriza won a landmark general election victory Sunday after campaigning on a pledge to renegotiate the bailout deal and seek forgiveness of more than half the debt.
Moody’s ratings agency on Tuesday described the election result as “credit negative” because it would prolong risks to financing, economic growth and banks’ liquidity.
The main stock index in Athens fell on the news, and was down 5.4 per cent in afternoon trading, amid losses across Europe.
Tsipras chose economist and veteran left-wing politician Giannis Dragasakis as deputy prime minister and expanded powers for the ministries of development, environment, interior and public works — reducing the number of ministries from 19 to 11.
Varoufakis had revealed his appointment earlier yesterday in a private blog post.
“Naturally, my blog posts will become more infrequent and shorter,” he wrote. “But I do hope they compensate with juicier views, comments and insights.”