(Adds details, more analyst comment)
By Camillus Eboh
ABUJA, Dec 2 (Reuters) - Nigerian President Umaru Yar'Adua proposed a 2.87 trillion naira ($24 billion) 2009 budget on Tuesday, a slight increase over actual spending for this year despite falling revenues due to lower world oil prices.
The 2009 draft budget, which can be amended by legislators, assumed federal government revenues in the world's eighth biggest oil exporter of 1.778 trillion naira in 2009, compared to 2.59 trillion originally projected for this year.
"The changing international oil market poses great concerns for our fiscal outlook," Yar'Adua told parliament.
"The international financial crisis has led to slowing growth across the world economy, resulting in lower demand for our commodities, in particular crude oil," he said.
The budget proposal made conservative assumptions on oil revenues, setting the benchmark oil price at $45 against $59 this year and forecasting oil output of 2.29 million barrels per day down from 2.45 million bpd in the 2008 budget.
But economists warned of a widening deficit.
"The authorities have taken a very prudent approach on the revenue side, which should provide more protection against volatile global markets," said Mike Hugman, emerging markets strategist at Standard Bank.
"However, with spending being kept roughly flat versus 2008 in order to avoid a negative fiscal shock, this will involve a much larger deficit," he told Reuters.
"The increased level of bond issuance that may be required could push up interest rates in 2009."
The naira currency weakened to between 128-130 to the U.S. dollar on the interbank market after the budget proposal, having opened at around 120 to the dollar earlier, dealers said.
OPTIMISTIC GROWTH FORECAST
The spending plans represent an 8.4 percent increase on the 2008 budget, revised to 2.65 trillion naira in November.
Total approved government spending for 2008, including a supplementary budget also signed into law last month, is around 3.3 trillion naira, but not all of those funds have been used.
Yar'Adua said the budget proposal was based on economic growth of 8.9 percent in sub-Saharan Africa's second-biggest economy and inflation of 8.2 percent. Economic growth was running at around 6.5 percent this year, he said earlier.
"There were no major initial surprises ... with the exception of an optimistic GDP growth forecast -- 8.9 percent is not easily achievable," said Richard Segal, emerging markets economist at UBA Capital.
"Although the spot oil price is only 10 percent above the official target, belying the government's traditional conservatism, the December 2009 futures market discounts a $61 per barrel oil price," he said.
The budget included $5 billion earmarked for funding joint venture projects with foreign oil companies.
Funding shortfalls at state-run oil company NNPC, which operates joint ventures with firms including Royal Dutch Shell, ExxonMobil, Chevron and Total, have limited oil output from Africa's top producer.
Yar'Adua said oil production this year had averaged 2 million barrels per day, below initial expectations.
(To see FACTBOX-Key Nigerian budget assumptions please click on)
(For full Reuters Africa coverage and to have your say on the top issues, visit: http://africa.reuters.com/ ) (Writing by Nick Tattersall and Randy Fabi; Editing by Ron Askew)