EFERio de Janeiro

The Brazilian government plans to hold an auction of oil and gas exploration rights in October, the National Petroleum Agency, or ANP, said.

The new auction, the 13th since the government ended Petrobras's monopoly over the industry in 1998, will offer interested energy companies the opportunity to bid for exploration and production rights on 269 blocks in 10 basins, the ANP said in a statement.

Companies will be able to bid on both onshore and offshore blocks, but the auction does not include the pre-salt reserves, which are off southeastern Brazil and considered one of the largest oil finds in recent decades.

The pre-salt layer is found beneath the sea bottom and contains a gel-like deposit of salt that could be up to two kilometers (1.24 miles) deep.

The auction was originally scheduled for the first half of this year, but the government said in March that it was postponing it due to the sharp drop in oil prices and the corruption scandal at Petrobras.

The blocks being auctioned off are in the Amazonas, Parnaiba, Potiguar and Pelotas basins, all onshore areas, and the Reconcavo, Sergipe-Alagoas, Jacuipe, Camamu Almada, Campos and Espiritu Santo offshore basins, the ANP said.

Some 36 percent of the new reserves discovered around the world in the past five years are in Brazil, the government said.

Brazil held oil rights auctions regularly between 1999 and 2000, but it halted them temporarily to change the regulations to increase the government's share of the profits from the pre-salt reserves.

The auctions resumed in 2013, when offshore and onshore blocks were put up for bidding.

At the last auction, held in November 2013, the ANP awarded only 30 percent of the 240 concessions offered because the majority of the blocks were in largely unexplored areas with the potential to mainly yield natural gas and non-conventional gas.