SAO PAULO (Reuters) - Restructuring firm PJT Partners will step down as financial advisor to Brazilian phone carrier Oi SA <OIBR4.SA>, which filed for the country's largest-ever bankruptcy protection in June, two sources with direct knowledge of the matter said on Friday.

PJT and Oi are discussing the size of a break-up fee and the company will start looking for a new financial advisor as early as next week, the sources said. The advisor had disagreements with part of Oi's board over the restructuring, the sources added. Oi declined to comment and PJT did not immediately have a comment.

(Reporting by Tatiana Bautzer and Guillermo Parra-Bernal; editing by Diane Craft)