Brazilian conglomerate Odebrecht is poised to agree on the sale of its controlling stake in compatriot petrochemical producer Braskem to LyondellBasell by mid-October, according to a report by Brazilian financial newspaper Valor Econômico.

By that time, the paper said, Braskem’s other major shareholder, oil giant Petrobras, will decide whether to include its own stake. This would allow the transaction to be wrapped up as one and submitted to regulators.

Odebrecht currently owns 50.1% of Braskem's voting capital, while Petrobas holds 47%. LyondellBasell and Odebrecht confirmed last month that they were in exclusive talks for the Dutch-headquartered, US-managed chemical producer to acquire control of Braskem in a cash-and-shares deal.

Valor calculates that Odebrecht’s stake could be worth more than 21 billion Brazilian reais ($5.4 billion), which would place Braskem’s value at about 55 billion reais ($14.3 billion).