After an investigation into alleged cartel conduct lasting several years the Australian Competition and Consumer Commission has launched action against the steelmaker in the Federal Court.

Former general manager of sales and marketing senior manager Jason Ellis is also part of the action.

The ACCC alleges the steelmaker and Mr Ellis tried to "induce agreements" with competitors to fix or raise prices for flat steel product made at Port Kembla from September 2013 to June 2014.

The ACCC is seeking penalties and costs against both BlueScope and Mr Ellis, as well as an order disqualifying him from managing corporations.

In a statement BlueScope noted that the ACCC did not allege that any agreement was reached.

"These are serious allegations and the board is treating them very seriously," said BlueScope Chairman John Bevan in a statement to the Australian Stock Exchange.

"Since becoming aware of the ACCC's investigation, we have constructively engaged with the ACCC and conducted our own internal investigation.

"While we have not seen all of the evidence that has been relied on by the ACCC, based on what we know today, we do not believe that BlueScope, or any current or former employees, have engaged in cartel conduct."

Former BlueScope CEO Paul O'Malley announced the ACCC was investigating BlueScope employees back in 2017.

"Over the last financial year the ACCC has been investigating potential cartel conduct by BlueScope relating to the supply of steel products in Australia that involved a small number of BlueScope employees in the period from late 2013 to mid 2014," Mr O'Malley said.

"BlueScope has co-operated and is continuing to co-operate with the ACCC's investigation."

In August last year new CEO Mark Vassella said the investigation was ongoing and he was "uncertain what the outcome will be".