RIO DE JANEIRO, Sept 24 (Reuters) - Brazilian

environmental agency Ibama approved Petrobras' emergency

response test in the Foz do Amazonas basin, while also

requesting some adjustments be made before granting the

state-run oil firm a license to drill in the environmentally

sensitive offshore region, documents seen by Reuters showed on

Wednesday.

The area, in the northernmost part of Brazil's Equatorial

Margin, is considered Petrobras' most promising oil frontier,

sharing geology with nearby Guyana, where Exxon Mobil ( XOM ) is

developing huge fields.

In 2023, Ibama denied Petrobras a request to drill

there, which the company immediately appealed, stoking divisions

in Brazil's government between environmental advocates and

allies pushing for oil and gas development in the region.

For Petrobras, the emergency response test was the final

stage of the environmental licensing process.

With the Ibama report completed, the head of the agency,

Rodrigo Agostinho, can make a final decision to grant or deny

the license.