A top aide of the general confirmed the resignation but said nothing about any plan to run for president.

As army commander, Fonseka led the final phase of the war against the Liberation Tigers of Tamil Eelam which ended in May with the killing of LTTE leader Velupillai Prabhakaran and the rest of the rebel hierarchy.

The Sri Lankan press has for the last several days speculated that Fonseka is likely to run on the opposition ticket against President Mahinda Rajapaksa.

Political analysts believe that the general is the most credible opponent the opposition parties can field against Rajapaksa, who is widely expected to seek reelection two years before his current six- year term ends to capitalize on the victory over the rebels.