(Adds details on import, export flows)
BUENOS AIRES, Dec 19 (Reuters) - Argentine imports slid in November under tight trade restrictions but exports fell even harder, driving the third straight monthly contraction in the trade surplus the South American country relies on for dollar supplies.
Imports plunged 19 percent to $4.82 billion and exports dropped 20 percent to $5.28 billion, government data showed on Friday, underscoring economic weakness both in the domestic economy and abroad.
The trade surplus narrowed 34 percent in November from the same month a year earlier to $461 million, undershooting market expectations.
The median forecast in a Reuters poll of seven analysts was for a surplus of $650 million.
President Cristina Fernandez's leftist government relies on the surplus to boost dollar liquidity on the tightly controlled currency market.
It tightened trade and currency controls after defaulting on its debt for the second time in twelve years in July, an event that triggered a surge in capital flight and heaped more pressure on the central bank's low foreign reserves.
Largely cut off from global capital markets, Argentina relies heavily on its reserves to help cover energy import costs, service its debt obligations and prop up the peso currency. (Reporting by Maximiliano Rizzi, writing by Richard Lough; Editing by Chris Reese and Meredith Mazzilli)