BEIJING, May 29 (Reuters) - China's new policy on mixedrubber imports will affect 50% of such imports from Thailand andall such imports from Vietnam, an official from the nation'snatural rubber association said on Wednesday.

China's General Administration of Customs is believed tohave stepped up inspections of mixed rubber, or natural rubberthat is improved through addition of chemicals, to ensureimporters are not mislabeling shipments as mixed rubber to takeadvantage of a lower tariff rate on the substance. Rubber priceshave climbed as a result.

The association has suggested the government set a newtechnology standard for mixed rubber imports to facilitateshipments, Zheng Wenrong, vice president of China's NaturalRubber Association, told Reuters on the sidelines of aconference.

(Reporting by Meng Meng and Shivani Singh; Writing by HallieGu; editing by Christian Schmollinger) ((Hallie.Gu@thomsonreuters.com; +86 10 6627 1250; ReutersMessaging: hallie.gu.thomsonreuters.com@reuters.net))