SAO PAULO, Sept 21 (Reuters) - Brazilian antitrust watchdog CADE decided on Wednesday to give steelmaker Companhia Siderurgica Nacional, known as CSN, additional time to sell the stake it owns in rival Usiminas.

CADE councilors voted to allow CSN more time to sell the stake, but kept the need to divest present in the 2014 decision by CADE. Superintendent Alexandre Barreto had proposed allowing CSN to keep the stake, but this was rejected by the councilors. (Reporting by Alberto Alerig and Tatiana Bautzer Editing by Chris Reese)