Colombian Agriculture Minister Juan Camilo Restrepo, who dealt with paralyzing strikes by coffee growers and has aided negotiators seeking a peace accord with Marxist rebels, said on Friday he had submitted his resignation.
The effective date of his departure is unclear. Restrapo told reporters he informed President Juan Manuel Santos more than a month ago that he planned to step down but would remain in office until a replacement was named.
There has no been announcement on a successor.
Local radio Caracol quoted Restrepo as saying he would stay in his post until an agreement was reached with the Revolutionary Armed Forces of Colombia, or FARC, on land reform, the first and thorniest item on a five-point agenda.
FARC and government negotiators have been discussing land reform for almost seven months, with both sides hinting recently that they are close to agreement.
Restrepo has been heavily involved behind the scenes in government talks with FARC that aim to bring an end to five decades of war.
He became the first minister to resign before the May 31 deadline for Cabinet officials who want to run in the 2014 presidential election. But he said he was not interested for now in running for office. There has been media speculation that he would seek the Conservative Party candidacy.
"I consider that certain cycles and important tasks that the president charged me with are ending," Restrepo, 66, told reporters. "We'll see what the days and future bring, but it's not the reason or the motivation for my resignation."
Among other government officials expected to resign before elections is Housing Minister German Vargas Lleras, Santos' likely choice for president if he does not himself seek re-election.
As agriculture minister, Restrepo has struggled with numerous protests since joining Santos' Cabinet in 2010.
A former finance minister and senator, he led difficult negotiations in late February that ended a two-week strike by coffee farmers who blocked roads and stalled domestic sales in the world's top producer of high-quality Arabica beans. Cacao growers joined the strike.
He helped clinch agreement with potato farmers earlier this week after a demonstration over prices.
Protests, strikes and bombings across Colombia's commodities sectors have dampened economic growth and hurt Santos' popularity, at a time when he is trying to end a war with the FARC and mulls a re-election bid.