"He did not give us any reason for the dissolution of the Cabinet. Permanent secretaries will take charge of the ministries from tomorrow," outgoing Information Minister Dora Akunyili told reporters after a lengthy Cabinet meeting.

The powerful governors of Nigeria's 36 states and senior ruling party officials should now put forward nominees for new ministers who will then be screened and approved by the Senate, a process which could take weeks, Reuters reported.

In the interim, Jonathan is the sole administrator of Africa's most populous nation and biggest oil and gas producer, because as acting president he has no deputy in the presidency.

Jonathan took over as acting leader in early February during the three-month absence of ailing President Umaru Yar'Adua who was undergoing medical treatment in a Saudi clinic. Yar'Adua has since returned to Nigeria but remains too sick to rule.

Yar'Adua's secretive return in the middle of the night raised fears among diplomats, investors, political analysts and the opposition that his inner circle of aides, led by his wife Turai, would fight to maintain their influence and seek to undermine Jonathan.

The Cabinet was made up largely of Yar'Adua appointees.

"A point had come where there was a disconnect between the cabinet and leadership (in the presidency), so it's only fair for him to pick his own team," Bismarck Rewane, head of Lagos-based consultancy Financial Derivatives, told Reuters.

"It's difficult for him to deliver on his programs with another man's team," he said.

Jonathan has moved quickly to assert his authority. He had already demoted the former justice minister -- a close Yar'Adua ally -- and appointed respected ex-military general Theophilus Danjuma as one of his top advisers.

He also sacked the country's national security adviser, a key member of Yar'Adua's inner circle.

Published: 17 March 2010 18:02 GMT  | Last updated: 18 March 2010 06:59 GMT