MOSCOW, Sept 6 (Reuters) - Russia plans to start issuing replacement bonds in the fourth quarter of this year to substitute sovereign Eurobonds that it can no longer service because of Western sanctions, a finance ministry official said on Wednesday.

Denis Mamonov, head of the ministry's debt department, also told reporters that the level of government borrowing in 2024 would be comparable with this year's.

Mamonov said potentially all Eurobonds could be replaced, but this was still under discussion. The new paper would be traded on the Moscow Exchange.

"This is not the replacement of Eurobonds with OFZs, this is the replacement of Eurobonds with the same paper, with the same structure, pegged to foreign currency, but with all settlements in roubles," he said. (Reporting by Elena Fabrichnaya, writing by Mark Trevelyan, editing by Andrew Cawthorne)