LONDON/NEW YORK - A group of Zambia's international bondholders has signed a non-disclosure agreement with the government to discuss a $3 billion debt restructuring proposal, three sources familiar with the situation said on Tuesday.

The government sent a formal debt rework proposal to the steering committee of the creditor group last week, two of the sources said. Entering into a non-disclosure agreement usually marks the start of formal restructuring talks.

A Zambian finance ministry spokesperson did not immediately respond to a request for comment. Advisers for the creditor group declined to comment.

Zambian President Hakainde Hichilema in late February said the last remaining official creditors, China and India, had signed restructuring agreements, raising hopes that the much-delayed restructuring process would soon be finished.

The official creditors had objected to previous bondholder deals on the grounds that they did not offer comparable debt relief to theirs, but did not say at the time what the bondholders needed to propose instead.

Zambia has three defaulted bonds outstanding, with original maturities in 2022, 2024 and 2027.

Zambia was the first African country to default in the COVID-19 era, in late 2020, but its restructuring process has been beset by setbacks, with the rejection of the bondholder deals last year being only the latest.

(Reporting by Libby George, Rodrigo Campos and Rachel Savage; Editing by Karin Strohecker, Leslie Adler and Mark Porter)