By Cynthia Kim and Hayoung Choi

SEOUL (Reuters) - South Korea's exports contracted at their steepest pace in nearly three years in February as demand form its major market China cooled further in yet another sign of faltering momentum in Asia's fourth-largest economy.

Overseas sales dropped 11.1 percent in annual terms, the sharpest decline since April 2016 and the third month of falling shipments. A Reuters survey had predicted a 10.8 percent decline for February.

The deepening export slump comes at a time of slowing global growth as the Sino-U.S. trade conflict disrupts world supply chains in a blow to business investment and corporate profits.

Imports shrank by 12.6 percent in February from a year earlier, also worse than a 11.6 percent fall seen in the survey. This resulted in trade surplus of $3.1 billion, more than double the amount in January as imports dropped at a faster rate, according to the Korea Customs Service.

Though trade negotiations between Washington and Beijing appear to be making some progress, export-driven Asian countries including South Korea, Japan and Taiwan are reeling from the ripple effect of the months-long trade war.

Cooling demand from China, which buys nearly 30 percent of South Korean export goods, has put an increased strain on the economy, deepening worries about its key exports items bound for China - memory chips and petroleum products.

As South Korea's exports got off to a shaky start this year with inflation showing no sign of reviving, the central bank on Thursday left the base rate unchanged at 1.75 percent.

(Editing by Shri Navaratnam)