(Adds comment from representative for Antontello)

RIO DE JANEIRO/LONDON, Sept 24 (Reuters) - Debut trading in Hygo Energy Transition Ltd was suspended on Thursday hours after the liquefied natural gas transport and infrastructure operator's chief executive was named in a corruption investigation in Brazil.

Hygo is headed by Eduardo Antonello, a former executive of offshore oil rig company Seadrill Ltd who Brazilian federal prosecutors accused of bribery in court filings outlining a new phase of the massive Car Wash graft probe.

A representative for Antonello, who is now based in London, said the search warrants were executed on the basis of "false" plea bargain testimony. The representative criticized Brazilian authorities for allegedly impugning the professional reputations of people being investigated before all the facts were known.

Hygo, a joint venture between Golar LNG Limited and U.S. private equity firm Stonepeak Infrastructure Partners whose shares had been due to be floated in New York, did not confirm or deny an IPO cancellation, its press office said by e-mail. Stonepeak did not immediately reply to a request for comment.

Golar said the allegations against Antonello "involve conduct that predates and does not, in any way, implicate his work at Hygo."

"However, in an abundance of caution, Hygo has initiated a review to seek to confirm that there have not been any deviations from its culture of compliance in connection with Mr. Antonello's service to Hygo," the company said in a statement.

Pricing of Hygo's shares was due to take place on Thursday, but the New York Stock Exchange said they had been suspended without providing a reason.

Shares in Golar were down more than 25% in trading in New York on Thursday.

Hygo announced in September its plan to raise $485 million in an initial public offering, with shares ranging from $18-$21 apiece, according to a regulatory filing.

As part of the latest phase of the Car Wash probe, a corruption investigation that in six years has led to the jailing of two former Brazilian presidents and hundreds of executives and politicians, Brazilian and Dutch police executed dozens of search warrants on Wednesday.

According to Brazilian federal prosecutors, the current phase involves Seadrill as investigators deepen ongoing probes into three contracts worth $2.7 billion that were signed in 2011 by Malaysia's Sapura Energy Berhad and Brazil's state-controlled oil firm Petroleo Brasileiro SA.

Sapura strongly refutes any involvement in any form of bribery or corruption in its business dealings in Brazil and anywhere else in the world, the company said on Thursday in a statement.

The investigation is in its early phases and the details were first disclosed by Brazilian federal prosecutors on Wednesday. No one has been formally charged.

Antonello worked for Seadrill at the time and was responsible for establishing the company's Brazilian operations. Court documents in Brazil show his phone was wiretapped and his e-mail monitored by the police.

Seadrill confirmed its subsidiary Seadrill Serviços de Petroleo Ltda was served on Wednesday with a search and seizure warrant from federal police in Rio de Janeiro. It said it is cooperating fully with the ongoing investigation.

Seadrill's shares closed 6.5% down on Thursday in Oslo.

The contracts between Sapura and Petroleo Brasileiro, for the construction and charter of three pipe-laying support vessels, known as PLSVs, are still in effect today, prosecutors said. (Reporting by Sabrina Valle and Gram Slattery in Rio, and Jonathan Saul in London; Additional reporting by Niket Nishant and Luciano Costa; Editing by Christian Plumb and Daniel Wallis)