LONDON: Sri Lanka's international bonds tumbled some 3 cents on Monday as investors worry an election win by Marxist-leaning Anura Kumara Dissanayake could see him revisit the terms of the country's International Monetary Fund bailout and debt rework.

Dissanayake, who won the Saturday ballot running for the National People's Power (NPP) alliance, took office as president on Monday, promising change in the island nation emerging from its worst economic crisis in more than seven decades.

Shorter-dated bonds suffered the biggest falls, with the 2025 maturity down 2.9 cents to be bid at 49.28 cents, Tradeweb data showed.

"On the economic front, the NPP has stated that it would be looking to renegotiate parts of the $2.9 billion IMF program," JPMorgan's Toshi Jain said in a note to clients.

"Some of its leaders have expressed displeasure with the terms of the debt restructuring while Mr. Dissanayake has stated that he is committed to debt repayments."

Sri Lanka's $2.9 billion bailout has been key to the country's recovery from economic crisis, and the fund is due to undertake a regular review of reform progress which, once passed and signed off by the executive board, triggers a payout of funding tranche. The IMF's next review had been due on Oct. 1. The Fund did not immediately respond to a request for comment.

A second source of concern for investors was that the change in government could also lead to a renegotiation of a long-sought debt deal finalised with bondholders last week.

"A Dissanayake win is the worst possible outcome for Sri Lanka’s bonds, raising question marks not only for the IMF programme but also whether a new administration would honour the agreement reached with creditors on 19 September," Hasnain Malik at Tellimer said in a note to clients. (Reporting By Libby George and Karin Strohecker; Editing by Amanda Cooper and Andrew Cawthorne)