Petrobras (PBR) said Thursday it will not exercise its preemptive or tag-along rights in a potential sale of Braskem (BAK) shares held by NSP Investimentos, a Novonor subsidiary, according to a regulatory filing.

The decision relates to a possible transaction in which Shine I Fundo de Investimento em Direitos Creditorios would acquire the NSP-held stake. Petrobras' board approved the move on Wednesday and authorized the company's executive team to take the necessary steps, the filing said.

Petrobras said it will update the market on any material developments, including when it receives the final terms of the proposed transaction.

Petrobras shares fell 3.7% in recent Thursday trading, and Braskem dropped 12%.

Price: 15.24, Change: -0.59, Percent Change: -3.72