HAVANA (Reuters) - Colombia's government and FARC rebels are incorporating changes into the peace deal that was rejected in a referendum earlier this month in a bid to swiftly salvage the accord, both sides said on Friday.

The government and rebels are back at the negotiating table in Havana where they have been holding talks for four years on ending a 52-year old conflict that has killed more than 220,000 people.

"We have analyzed the proposals of changes and precisions to the final accord that different sectors of the society have suggested," they said in a joint statement that they read out in a news conference in Havana.

"The proposals are being discussed carefully and many are being incorporated into the texts of a new accord," the statement said, without describing the proposed changes.

Colombian voters rejected the original deal by a razor-thin margin of less than half a percentage point, with opponents saying it was too lenient on the Marxist rebels.

Led by hardline former President Alvaro Uribe, the "No" side was outraged the accord offered the FARC ten congressional seats and did not foresee jailing the rebels' leaders.

Although the FARC leadership has said it is willing to hear new ideas, Uribe's proposals may be difficult to accept, given they have repeatedly refused to consider jail time and want to form a political party.

On Friday, the FARC and government delegations said they would pick up talks next Thursday Nov. 3, "with the aim of reaching quickly and efficiently a new definitive agreement."

Colombian President Juan Manuel Santos, who has staked his legacy on ending the war with the FARC and earlier this month won the 2016 Nobel Peace Prize for his efforts, said in a statement on Friday that time was of the essence.

"The ceasefire we agreed is fragile," he said. "We need a new agreement right away."

(Reporting by Nelson Acosta; Writing by Sarah Marsh; Editing by Andrew Hay)