LONDON, Nov 23 (Reuters) - Royal Dutch Shell (RDSa.L) has launched talks with investors to secure support for its plan to relocate its headquarters from the Netherlands to Britain, sources said, as a leading advisory recommended backing the move at a December vote. Shell said this month it would scrap its dual Anglo-Dutch share structure and move its head office to London from The Hague due to the Dutch tax system and after a court ruling over its strategy to reduce greenhouse gas emissions. read more The company also plans to move its tax residence to Britain and drop "Royal Dutch" from its name - part of its identity since 1907 - to become Shell Plc. Shareholders will vote on the changes at a special general meeting on Dec. 10 where the resolution needs to secure more than 75% of votes cast. To secure the high threshold, Shell"s management has in recent days set up more than 100 meetings with leading investors, two sources close to the process said. "We believe this is a very shareholder-friendly proposition and we"re working hard and engaging with many of our shareholders to explain all of the benefits of this move and encourage them to vote," a Shell spokesperson said. Proxy advisory Glass Lewis, which advises major funds, recommended shareholders vote in favour, in a note seen by Reuters. The simplified structure would allow "an acceleration in distributions by way of share buybacks, as there will be a larger single pool of ordinary shares that can be bought back," Glass Lewis said. It would also strengthen Shell"s ability to manage its energy transition, it added. Reporting by Ron Bousso; Editing by Edmund Blair