BUENOS AIRES, Dec 2 (Reuters) - A potential deal for Argentina with the International Monetary Fund (IMF) to roll over some $45 billion it owes would be a key breakthrough, but not enough on its own to push up the embattled country"s credit rating, Moody"s said on Thursday. The South American country, which defaulted and restructured its sovereign bonds last year, is locked in talks with the IMF to replace a record facility from 2018 that failed to keep the grains producer from slipping into economic and currency crises.That new deal will require the two sides to agree on a multi-year economic plan, which Argentina"s government is hoping to send to Congress this month. Gabriel Torres, a senior analyst at Moody"s Investors Service, told reporters that a deal and economic plan was "essential, but not enough for an overall credit enhancement" from the current "Ca" level, the second lowest rating. "Is it an important step? Yes. But just as important, if not more, is that (the plan) is fulfilled and maintained over time." Torres said that striking a deal would likely generate a positive reaction in the markets, but it could be short-lived. "Is it an important step? Yes. But just as important, if not more, is that (the plan) is fulfilled and maintained over time." Torres said that striking a deal would likely generate a positive reaction in the markets, but it could be short-lived.