A 24-hour anti-austerity strike in Greece Thursday is expected to disrupt public transportation, close schools,and reduce staffing at hospitals.

The strike, which will include protest rallies by unions in the capital, Athens, represents the first challenge for the three-week-old coalition government of new Prime Minister Lucas Papademos.

Late Wednesday, Mr. Papademos' staff released a letter he sent to the European Union, European Central Bank, and the International Monetary Fund vowing to carry out austerity measures to secure bailout funding.

In the letter, Papademos wrote, “the government is determined to continue the process of fiscal consolidation and structural reform in order to secure public finances and improve the country's international competitiveness.”

On Tuesday, after receiving Mr. Papademos' letter, EU leaders approved the release of an installment of the bailout funds worth nearly $11 billion.

Under a new agreement reached with European leaders in October, Greece could receive up to $174 billion in bailout funding and possibly have some of its bond debt reduced.

The additional funding is contingent on the Greek government implementing austerity measures, including reducing the size of the work force and salaries.