The International Monetary Fund's executive board Thursday approved a EUR28 billion ($36.49 billion) loan for debt-beleaguered Greece despite fears by some members that political risks may derail the program.

The decision allows for an immediate disbursal of the first EUR1.65 billion tranche of the loan.

As a small share of joint program with the European Union, the loan helps Athens stave off default and the euro zone to temporarily prevent the debt contagion from spreading to other ailing countries in the region.

Still, several board members have expressed reservations about the ability of Greece to successfully carry out the four-year program.

The IMF has repeatedly said the Greek program runs a very high risk of derailment given the depth of economic restructuring required for the joint IMF-European Union package. The IMF is especially wary given Greece's track record of failing to meet many of its fundamental program targets.

-By Ian Talley, Dow Jones Newswires; 202-862-9285; ian.talley@dowjones.com