SAO PAULO, Sept 5 (Reuters) - Société Mondiale, a minority shareholder in Brazil's largest fixed-line carrier OI SA , said on Monday an arbitration ruling obliges the company to hold a shareholders' meeting on Sept. 8 as demanded by the activist investor.
The ruling was issued on Sept. 5 by the arbitration chamber of the Brazilian stock market operator BM&F Bovespa SA , according to documents sent to Reuters by the investor.
Oi is operating under bankruptcy court protection and on Monday filed a reorganization plan aimed at reducing 65.4 billion reais ($20.03 billion) of bond, bank and regulatory liabilities.
The shareholders' meeting was called by the activist investor in August but was suspended on Friday by the judge in Rio de Janeiro overseeing the bankruptcy proceedings.
Société Mondiale is seeking to remove all Oi board members appointed by majority shareholder Pharol SGPS.
Oi refused to comment on the arbitration proceedings.
Pharol said Monday's arbitration ruling causes "confusion" in the wake of the bankruptcy court's decision from last week, which suspended the shareholders' meeting and ordered a mediation between the dissenting parties within 20 days.
Oi succumbed to heavy debt and years of boardroom skirmishes and shareholder dissent. ($1 = 3.2643 Brazilian reais) (Reporting by Ana Mano; Editing by Muralikumar Anantharaman)