* Thailand, Indonesia, Malaysia say to “manage” rubber exports
* Minister declines to give details on how step will work
* Analysts doubt measure will raise battered prices (Recasts; adds analyst comment, detail)
By Yantoultra Ngui and Manolo Serapio Jr
KUALA LUMPUR/SINGAPORE, Nov 20 (Reuters) – Top Asian rubber producers have agreed to “manage” exports to international markets to curb excess supply, although analysts saidthe step would have little impact on battered prices without a robust pickup in demand.