Angola's president has moved the head of state oil firm Sonangol into the government to coordinate economic policy, state news agency Angop reported, a move likely to fuel speculation that Manuel Vicente has been selected to succeed Eduardo dos Santos.
In September, weekly newspaper Novo Jornal cited ruling MPLA party sources as saying that Dos Santos had selected Vicente, 55, as his successor to take over before or after an election later this year.
Vicente's reappointment as Sonangol CEO for a third term last month quashed some of the speculation, but analysts said the president still held the option to remove him from the company at any time.
Earlier on Monday, the government approved a presidential decree for Vicente's departure from Sonangol and Angop later cited a presidency statement saying Dos Santos had appointed him as economic coordination minister.
The role is a new one, created by Dos Santos to boost the effectiveness of the government's economic decisions. Vicente is likely to have wide-ranging policy-making powers and will report directly to the president.
"Vicente should not be discounted as a possible candidate for the succession. He is very close to the president, an ally who the president trusts," said Markus Weimer, an Angola expert and analyst at London-based thinktank Chatham House.
"The fact that top positions in Dos Santos' inner circle are being changed in the run up to an election doesn't surprise me. It's part of his strategy, to keep his cards close to his chest and keep everyone guessing about his plans."
The parliamentary election, to be held in the third quarter, will be only the second in Angola since the end of a devastating 27-year civil war in 2002, with the head of the winning party's candidate list becoming president.
Dos Santos, who has been in power since 1979 and is Africa's second-longest serving leader after Equatorial Guinea's President Teodoro Obiang Nguema Mbasogo, has signaled he is ready to lead the party in the ballot, but has yet to confirm his decision despite promising to do so in January.
Angola is Africa's second-largest oil producer after Nigeria, and Sonangol plays a huge role in an economy in which oil revenues represent over 95 percent of export income and almost half of the gross domestic product.
Dos Santos' government and Sonangol have, however, long been accused of mismanaging oil revenues. Last month Human Rights Watch urged the government to account for $32 billion missing from state funds thought to be linked to Sonangol.
The government later denied the funds were missing and the IMF said last week it expected the authorities to account for most of the funds.
Angop added that Vicente, who built a strong reputation among international oil companies during his 13 years at the head of Sonangol, will be replaced by board member Francisco de Lemos Jose Maria.
"Vicente was respected by Angola's international oil partners, he was seen as someone they could do business with. That has now changed with his exit, so we'll have to see whether his replacement can build the same type of relations," Chatham House's Weimer said.
Jose Maria joined Sonangol's executive board in late 2008, working as chief financial officer and was also selected for a second term in December.
He takes over the company at a time when it starts exploring ultra-deepwater or "subsalt" offshore blocks which mirror those off Brazil where major volumes of high-quality light oil have been discovered in recent years.
Last month the company signed 11 deals with seven oil majors to drill thousands of metres under the Kwanza Basin seabed.