Abu Dhabi National Oil Company (ADNOC) has made a fresh bid to buy a stake in Braskem, Latin America’s biggest petrochemical company, from Brazilian conglomerate Novonor.

ADNOC offered to buy 38.3% of Braskem for BRL10.5 billion ($2.1 billion), the petrochemical firm said. Novonor, formerly Odebrecht, also owns 50.1% of Braskem’s voting rights.

Under the deal, Novonor’s creditors would receive half the sum in cash, and the other half would be financed by a seven-year 7.25% bond, Braskem said.

Creditors include local lenders Bradesco, Itaú Unibanco, Santander, Banco do Brazil and the Brazilian development bank BNDES.

ADNOC, which made a previous bid for the stake jointly with US private equity firm Apollo Global, is offering to pay BRL37.29 per share. Novonor would retain 3% of Braskem.

Braskem’s shares rallied 15.7% at BRL19.99 on São Paulo’s B3 exchange on Thursday afternoon.

ADNOC said in a securities filing it will carry out a due diligence before presenting a binding offer. Some liabilities may derive from an unresolved environmental conflict in the state of Alagoas in northeast Brazil.

State-run oil and gas company Petrobras, which has a 47% voting stake in Braskem and has a right of first refusal in the event of a potential change of ownership at Braskem, said Thursday it will evaluate the latest offer from ADNOC.

Petrobras added that for is also carrying out its own due diligence on Braskem for the “possible exercise of tag along or preemptive rights, in the event of the sale of the shares held by Novonor.”

Pedro Galdi, an investment analyst at Mirae Asset Management, said he does not believe Petrobras would buy a controlling stake in Braskem, but it is keen to keep its current shareholding in the firm.

“We are now entering a phase where all the interested parties, Odebrecht, Petrobras and financial creditors that hold shares as guarantees for past loans, have to assess the situation,” he told LatinFinance. “There are no obstacles [to the deal]: What is needed is that all parties involved agree to the conditions that are being put on table.”