Deputy Prime Minister Najib Razak will take over as premier "soon after" the end of the United Malays National Organisation (Umno)congress tomorrow the senior source said today.
Umno is the main party in government.
The source spoke on condition of anonymity and had direct knowledge of the plans which were the first concrete indication of Najib's economic and political policies.
"We expect many of these changes and reforms to be in place in less than a year, within 100 days of Najib taking office," he said.
Plans include reviewing the unwieldy Prime Minister's department which oversees law, parliament and internal security among other issues and streamlining ministries like Education and Higher Education as well as setting up a new Energy Ministry.
The government will also change management at top companies that are owned or part owned by the state, including plantations-to-property conglomerate Sime Darby.
Sime recently proposed the government build a new airport on land it owned, a proposal the government recently rejected.
"The aim is to enhance efficiency, because the government feels that the government-linked companies need to move away from its dependence on the government for its profits," said the source.