By Marco Trujillo
BARCELONA (Reuters) - Gabon's President Omar Bongo, Africa's longest-serving leader, died on Monday in a Spanish clinic where he was being treated for a serious illness, the Gabonese prime minister said.
Bongo's death after more than four decades in power leaves a political void in the oil-producing central African country which he tightly controlled. Senate President Rose Francine Rogombe, a Bongo ally in the ruling Gabonese Democratic Party, is expected to take over as interim leader.
La Vanguardia, a Barcelona newspaper with excellent contacts in the region, said on its website that Bongo, Africa's longest-serving leader had died at 1:00 p.m. British time (1200 GMT).
Gabonese Prime Minister Jean Eyeghe Ndong later confirmed his death in a news release distributed at the Quiron hospital in Barcelona.
Concerns over Bongo's health grew last month after he suspended his functions as head of state for the first time since taking power in 1967.
The 73-year-old checked into the clinic in Barcelona in May, officially to rest after the death of his wife. Reports that he was suffering from cancer fuelled speculation over who would lead the country if he died.
Although there have been some concerns about stability, analysts say the ruling party is likely to tightly manage the transition and Bongo's successes in easing ethnic tension will reduce the risk of turmoil.
Under the constitution, the country's interim leader should organise elections within 45 days.
Gabon's opposition say Bongo's son, Defence Minister Ali Ben Bongo, is being groomed to step in and question whether elections would be fair. Analysts see him, or another close family member, as most likely to take over.
Gabon has maintained close ties with former colonial ruler France and attracted investors with a Eurobond as well as its long-established oil industry. France's Total oil company is one of the country's biggest investors.
Oil output is in decline but oil revenues still account for about half of the country's income, even though they have been hit by falling world energy prices.
The country also has a $1 billion Eurobond (869,129 pounds), which is due to mature in 2017, and which the government is in the process of buying back..
(Additional reporting by Linel Kwatsi in Libreville and Vanessa Romeo in Barcelona; Writing by David Lewis; Editing by Nick Tattersall and Andrew Dobbie)
