AFP - Brazilian authorities said Monday they planned to impose fines exceeding $56 million (41 million euros) on US energy giant Chevron for the oil spill from a leaking well it operates off Rio de Janeiro state.

"The amount of the fine by the federal government will probably be of 50 million reals ($27.6 million), the maximum set for environmental damage, said Rio de Janeiro state's environment secretary Carlos Minc after meeting police officials probing the case.

The well, which Chevron said began leaking on November 8, is near the Frade field located some 370 kilometers (230 miles) northeast of Rio de Janeiro, in an area that is a migratory route for whales and dolphins.

Minc told reporters that Rio de Janeiro state also plans to slap a fine "that could be as high as 30 million reals" and added that there will be additional fines of more than 20 million reals for the damage caused.

And he said that Chevron could be barred from taking part in exploration tenders for five years.

"There will be no impunity in Rio" with respect to environmental offenses, he added.

Accusing the US energy company of "negligence", he said "they under-estimated the excessive oil pressure near a crack...This accident could have been avoided."

Minc said Chevron also failed to contain the leak.

Meanwhile, President Dilma Roussef was due to meet later Monday with the energy minister and the head of the National Oil Agency to discuss the fallout from the accident.

Chevron's Brazil country manager George Buch said the company "takes full responsibility for this incident...We are committed to deploying resources until the sheen can no longer be detected."

On Saturday, he told local media that "the pressure of the deposits was underestimated."

Based on an incorrect calculation, the company used a type of material that lacked sufficient weight needed to contain oil, which then leaked and reached the surface, Folha de Sao Paulo newspaper explained.

Chevron said the sheen, estimated at roughly 18 barrels or less in volume, was located about 120 kilometers (72 miles) off Brazil and continued moving away from the coast.

Buck had insisted the leak was fully contained on November 13, but noted that the incident was still being investigated.

According to Chevron, the slick reached a volume of 882 barrels of oil at its worst, a week ago Monday, and dropped to 18 barrels on Friday.

It estimated that between 200 and 330 barrels of oil a day have seeped into the sea since November 8. The energy ministry, for its part, said 220 to 230 barrels of oil were seeping into the ocean daily.

Those estimates were contested by Greenpeace, which said satellite pictures showed a spill "10 times bigger," and likely reached closer to 3,700 barrels a day.