Thirteen companies have been approved by Brazilian authorities to participate in a November oil bidding round for offshore exploration and production rights.

The companies were cleared to participate in the so-called 6th pre-salt bidding round, according to Thursday's edition of the government's official bulletin. Total signing bonuses are fixed at 7.85 billion reais ($1.92 billion).

The auction, scheduled for Nov. 7, is sizable by historical standards but significantly smaller than a so-called transfer-of-rights auction due to take place a day earlier. The government is expected to collect over $25 billion in signing bonuses at the Nov. 6 auction.

The list of participants on Nov. 7 is similar to those in the transfer-of-rights round. Two companies are participating in the 6th pre-salt round, but not the transfer-of-rights round: the Brazilian unit of Murphy Oil Corp and Repsol Sinopec Brasil SA, a joint venture between Spain's Repsol SA and China's Sinopec.

Companies signed up for the transfer-of-rights that are not included in the sixth round are the Brazilian units of France's Total SA, Portugal's Galp Energia SGPS SA and Norway's Equinor ASA.

However, in a Twitter post on Thursday, Brazil's ANP oil regulator said four more companies had applied to participate in the pre-salt round. ANP said it would evaluate the requests on Oct. 14.

Companies already approved for the pre-salt round include:

• BP Energy do Brasil Ltda, a unit of BP PLC
• Chevron Brasil Oleo e Gas Ltda, a unit of Chevron Corp
• CNODC Brasil Petroleo e Gas Ltda, an indirect unit of China National Petroleum Corp Ltd, or CNPC
• CNOOC Petroleum Brasil Ltda, a unit of China National Offshore Oil Corp (CNOOC)
• Ecopetrol Oleo e Gas do Brasil Ltda, a unit of Colombia's Ecopetrol SA
• Exxonmobil Exploracao Brasil Ltda, a unit of Exxon Mobil Corp
• Murphy Exploration & Production Co, a unit of Murphy Oil
• Petroleo Brasileiro SA, or Petrobras
• Petronas Petroleo Brasil Ltda, a unit of Petronas
• QPI Brasil Petroleo Ltda, a unit of Qatar Petroleum
• Repsol Sinopec Brasil
• Shell Brasil Petroleo Ltda, a unit of Royal Dutch Shell PLC
• Wintershall Dea do Brasil Exploracao e Producao, a unit of Wintershall Dea GmbH

($1 = 4.09 reais)

(Reporting by Gram Slattery and Marta Nogueira; Editing by Tom Brown)