FILE PHOTO: Brazil's anti monopoly watchdog Cade headquarters building is pictured in Brasilia, Brazil, August 7, 2017. Picture taken August 7, 2017. REUTERS/Adriano Machado/File Photo

RIO DE JANEIRO (Reuters) -Exxon Mobil, Brazilian state-run Petrobras and oil services provider TechnipFMC petitioned the country's antitrust regulator Cade to intervene in a merger between energy contractors Subsea7 and Saipem, public documents seen by Reuters show.

In filings submitted on Thursday, the firms said the merger between Norway's Subsea7 and Italy's Saipem would bring a level of concentration in the subsea oil and gas services market that could drive up costs and curb competition.

The firms want Cade to block the merger or impose remedies to preserve competition in Brazil, such as asset sales, a source with knowledge of the matter told Reuters.

Cade provided no additional information beyond what is in the public case file. Petrobras, Exxon, TechnipFMC, Saipem and Subsea7 did not immediately comment on the matter.

The combined group, to be renamed Saipem7, will have an order backlog of 43 billion euros ($50.6 billion), revenue of about 21 billion euros and core earnings of more than 2 billion euros, the companies said in a statement in July.

The deal is expected to be completed in the second half of 2026, the companies said.

In its filing with Cade, Petrobras said the transaction would impact the company, as it relies on the firms for its core business. Exxon said the deal would lead to a high concentration of contractors offering subsea umbilicals, risers and flowlines, or SURF projects, reducing competition and customer choice.

TechnipFMC, a rival services provider, said the deal would limit the ability of other players to compete.

(Reporting by Rodrigo Viga Gaier; Editing by Chizu Nomiyama Writing by Fabio Teixeira)