In its biannual report on the World Economic Outlook, the IMF, however, underlines that the fall in prices, which have fallen by half since June, offers "a much needed respite to oil-importing countries" in the region, which will benefit from a higher than expected growth.
Exporting countries, including the Gulf States, Yemen, Iran, Iraq, Libya and Algeria are expected to grow 2.4% this year against 3.9% forecast in October, before resuming the force in 2016 (3.5%).
"The sharp drop in oil prices weighed on the budget deficit and the external balance" of these countries contributing almost a third of world crude oil supply, according to the IMF.
Saudi, leader of the Organization of Petroleum Exporting Countries (OPEC), will see its growth limited to 3.0% against 4.5% in October.
Its budget "will experience a substantial deficit in 2015 and 2016," the IMF said, while a local report has already valued at over $ 100 billion this deficit for 2015, well beyond the 39 billion provided by the government.
The IMF also cut its forecasts for the other five members of the Gulf Cooperation Council (GCC) – Qatar, UAE, Kuwait, Bahrain and Oman -. Its report does not take into account the impact of Yemen’s war on the region’s economy.
Iran should benefit from a reduced growth to 0.6% and 1.3% this year and in 2016, against 2.2% and 2.3% expected in October, according to the IMF, which relies in particular on uncertainties related to the nuclear deal with the major powers.
In Iraq, the second largest producer in OPEC, whose economy contracted by 2.4% last year, growth is expected to reach 1.3% against 1.5% forecast in October.
For Algeria, the IMF now expects growth of 2.6% in 2015 against 4.0%.
The IMF had estimated earlier this year that the fall in prices would cost the GCC nearly $ 300 billion, almost half of their oil revenues. This will force them to "re calibrate their medium-term fiscal consolidation plans," the IMF underlines.
Conversely, oil-importing countries in the region see their growth prospects raised from 3.7% to 4.0% in 2015 against 3.0% last year. This is particularly the case for Egypt (+ 4% against 3.5% forecast in October).
IMF calls these countries to benefit from this positive environment to "continue reforms" in the Grants area "to stimulate spending that could improve growth."