The UK Competition Commission is extending the timeframe of a probe into Eurotunnel’s entry into the cross-Channel ferry sector.

The competition watchdog said the extension of the timeframe was because of the complexity of the inquiry into the purchase of three ferries from defunct SeaFrance.

The commission said it recognised that its preferred remedy of forcing the channel tunnel operator to divest the MyFerryLink business would clash with a ruling made by a French commercial court at the time of the deal last year.

The judgment by a Paris court that cleared the way for the takeover required Eurotunnel to hold on to the business for five years.

The French competition watchdog later cleared the deal, with restrictions.

The approach of its UK counterpart had been much tougher after its initial ruling found the deal created “a substantial lessening of competition” in the market.

But the commission yesterday put forward a number of other remedies for consultation.

One would see Eurotunnel forced to divest after the five-year lock-up period expired, with price controls in place in the interim.

Another would force MyFerrylink off certain routes, most notably Dover-Calais, as it is a “close substitute” for Eurotunnel services.

A further one was put forward by Eurotunnel for a “complete separation of commercial staff and management” between the parent and ferry operator.

A spokesman for P&O Ferries, which has complained about Eurotunnel’s entry into the ferry sector on competition grounds, said the company was “a little bit concerned” about the latest move by the UK watchdog.

“If they are going to water down the verdict then we would be concerned about it,” he told the Financial Times, arguing divestment is the only way to ensure a “level playing field”.

The Competition Commission denied it was backtracking.

“I wouldn’t go as far saying we are watering it down. We are just recognising there are legal complexities involved in some of the remedy possibilities,” a spokesman said.

Eurotunnel paid €65 million for the three ferries – Berlioz, Rodin and Nord-Pas-de-Calais – and started operating them under the new brand in August 2012.

Chief executive Jacques Gounon last month said he thought a compromise was possible between the UK and French regulators.