RIO DE JANEIRO, April 5 (Reuters) - Brazilian state-run oil company Petrobras PETR4.SA has completed work on a veterinary center in the Amazon region that is required for it to obtain an environmental permit for an offshore drilling project, the company said on Saturday.

The animal care center in the town of Oiapoque, Amapa state, is designed to assist animals in the event of an oil spill.

It was one of Brazilian environmental agency Ibama's main demands in response to Petrobras' proposal to drill offshore in the environmentally sensitive Foz do Amazonas region.

Amapa has granted the veterinary center an operating license but it still requires Ibama's clearance. Petrobras said in a statement it informed the agency the center will be available for inspection starting Monday.

The center is designed to care for birds, marine mammals, turtles, dolphins and manatees, said Petrobras, which aims to conduct exploratory drilling in a block 540 kilometers (325 miles) off Amapa's coast.

Foz do Amazonas in the so-called Equatorial Margin is Brazil's most promising oil frontier. It shares geology with nearby Guyana, where Exxon Mobil XOM.N is developing huge fields.

Ibama blocked Petrobras from drilling there in 2023, but the company filed a new request, which the agency is assessing. There is no deadline for a final answer.

(Reporting by Marta Nogueira; Writing by Gabriel Araujo; Editing by Cynthia Osterman)

((Gabriel.Araujo2@thomsonreuters.com; +55 11 5047-3352;))