TOKYO/SEOUL (Reuters) -- The Japanese government has reversed curbs on exports of photoresists to South Korea, one of three technology materials which it had restricted since July, a Trade Ministry official said on Friday.

The step comes as Prime Minister Shinzo Abe and South Korean President Moon Jae-in are expected to meet on Tuesday on the sidelines of a trilateral summit that includes China.

Japanese suppliers can now apply to export three years worth of photoresists rather than having to seek approval for each shipment separately, the official said.

South Korea gave a guarded welcome to the move by Japan.

"The latest measure was voluntarily taken by the Japanese government and is seen as partial progress, but we believe that this falls short of a fundamental resolution to exports curb issues," an official at the president's office said.

A South Korean trade ministry official told Reuters that photoresist export curbs were eased largely for shipments to Samsung Electronics, but said this was a "low-level of easing."

Samsung was not immediately available for comment.

The tighter curbs remain for two other tech materials -- fluorinated polyamides and hydrogen fluoride.

Japan produces around 90% of photoresists, used to transfer circuit patterns on to semiconductor wafers. South Korean companies have tried to source tech materials from non-Japanese companies, to cushion the impact of Japan's export curbs.