Japanese prime minister Yukio Hatoyama said deputy prime minister Naoto Kan will become finance minister, succeeding Hirohisa Fujii who is resigning due to ill health.
Yoshito Sengoku, administrative reform minister, will take on Kan's previous portfolio of National Strategy Minister.
Mr Fujii (77) was admitted to hospital for tests last week and later said he was worn out by wrangling over finalising Japan's budget.
One of the few experienced members of the novice Democratic Party-led government, Mr Fujii has often served as the voice of fiscal restraint. He was the main proponent of sticking to a cap of around 44 trillion yen (FX) on new bond issuance in the budget for the year starting April 1st.
Fujii's departure adds to the challenges piling up for the government as it wrestles with deflation, a fragile economy and huge public debt.
Reuters