Dec 8 (Reuters) - Transcanada Corp TRP.TO
* Siim Vanaselja designated as next Transcanada chair
* Transcanada - Vanaselja will succeed s. Barry Jackson, who will retire at close of Transcanada's annual meeting of shareholders in 2017 Source text for Eikon: ID:nCCN4lw4BH Further company coverage: TRP.TO