(Adds analyst comments, details and combines data sets)
* March exports -8.2 pct y/y, imports -13.8 pct y/y
* Exports see boost from steel, smartphones
* Shipments to China, U.S. both decline in March
By Christine Kim
SEOUL, April 1 (Reuters) - Improved shipments of smartphones and steel in March helped South Korea post its slowest decline in exports for four months government data showed on Friday, but weakness in sales to China remained a worry for the world's sixth largest exporter.
Exports in March fell by a less-than-expected 8.2 percent from a year earlier to $42.98 billion, the Ministry of Trade, Industry and Energy said. It was the slowest fall in exports since November last year.
The ministry said steel exports had rebounded by 14.7 percent in March on-year, while shipments of smartphones had surged 19.9 percent, mainly thanks to the release of Samsung Electronics Co Ltd's new Galaxy S7.
Imports dropped 13.8 percent to $33.16 billion to result in a $9.82 billion surplus, the Ministry of Trade, Industry and Energy said. The fall in imports was the slowest since June.
The trade performance beat median forecasts for declines of 10.4 percent and 13.1 percent for exports and imports respectively in a Reuters survey of 17 analysts.
Despite the improvement, the data failed to remove analysts' doubts about a rebound in global demand as the average export value per working day stood at $1.79 billion in March, less than $1.82 billion seen in February, Thomson Reuters calculations showed.
"I don't think we've hit bottom and there is no way exports growth will turn positive this year when looking at the state of the global economy," said June Park, economist at Daishin Economic Research Institute.
Exports to neighboring China, South Korea's biggest market, fell for a ninth straight month in March, the data showed. Shipments to the United States fell again after posting a brief rise in February.
Oil products continued to place a drag on exports as they plunged 41.6 percent last month in annual terms. The trade ministry said oil products, petrochemical goods and ships accounted for 69 percent of the exports decline in March.
RATE CUT UNCERTAINTY
Park said poor demand from China would keep dragging down exports.
With exports plunging from last year, the economy is now leaning on the sole crutch of domestic consumption, which has been showing a fragile recovery.
Many market participants expect the Bank of Korea to reduce its policy interest rate from an already record low of 1.50 percent in a bid to boost the economy, and possibly weaken the won currency.