* Export volumes fell 8 percent in January on year
* Import curbs bolstered 2012 trade surplus by 27 pct
BUENOS AIRES, Feb 21 (Reuters) - Argentina's January trade surplus shrank 49 percent from a year earlier to $280 million as imports grew for the first time since tough controls were put in place a year ago, the INDEC statistics institute said on Thursday.
The figure was below the $350 million median estimate in a Reuters poll of 11 analysts, whose forecasts ranged from $50 million to $1.23 billion.
In January 2012, the trade surplus was $550 million.
Growth in Latin America's No. 3 economy slowed sharply last year due to sluggish global demand, high inflation, a poor grains harvest, and the impact of government import and currency controls on business confidence and investment.
Drought slashed soybean and corn output in the 2011/12 crop year, reducing shipments abroad from the key global supplier.
In January, exports fell by 4 percent to $5.67 billion, while imports grew 1 percent from a year earlier to $5.39 billion. Prices for Argentina's exported goods rose but this was overpowered by a 8 percent decline in sales volume.
President Cristina Fernandez imposed tough new rules on purchases abroad in February 2012 that succeeded in bolstering the trade surplus last year by 27 percent compared with 2011.
Cooling domestic demand linked to the economic slowdown has also reduced imports.
The trade surplus is a key source of foreign currency in a country that uses the central bank's foreign reserves to pay debt. Argentina has been virtually locked out of global credit markets since its massive sovereign debt default in 2002.