* Exports fall 8 percent, imports steady despite controls
* Oilseed shipments sink 49 percent on smaller harvest
* Trade surplus through October stands at $11.53 billion
BUENOS AIRES, Nov 22 (Reuters) - Argentina's October trade surplus halved from the same month a year ago to $585 million , missing market expectations as exports fell, the government said on Thursday.
The figure came in below the $850 million median forecast given in a Reuters poll of six analysts whose estimates ranged from $585 million to $1.3 million.
Growth in Latin America's No. 3 economy has slowed sharply this year from sluggish global demand, high inflation, a poor grains harvest, and the impact of government import and currency controls on business confidence and investment.
That is affecting demand for Argentine exports and helping stifle demand for imported goods, which the government has sought to smother with tight controls imposed in February.
October's exports fell 8 percent to $6.9 billion while imports were virtually unchanged at $6.3 billion. It is the first time imports have not fallen since the controls took effect eight months ago.
Oilseed shipments, one of the country's main foreign currency earners, plunged 49 percent. Drought hit Argentina's soybean harvest in the 2011/12 crop year.
In the January-October period, exports are down 3 percent year-on-year while imports are 7 percent lower, the INDEC national statistics agency said.
The accumulated 2012 surplus of $11.53 billion is 24 percent bigger than it was during the same 10-month period of 2011.
In October 2011, the country's trade surplus totaled $1.16 billion.