Shares in Independent News and Media slumped nearly 15% today after it said it will see a "material" reduction in its expected full year pre-tax profit.

In a trading update, INM said this was partly due to legal costs related to the ongoing investigation by the Office of the Director of Corporate Enforcement and an independent review undertaken by the company. 

Both of these relate to a boardroom row between company chair Leslie Buckley and former chief executive Robert Pitt as the two disagreed over the price INM would pay to acquire radio station Newstalk, though the acquisition never went ahead. 

INM also said it was seeing challenging market conditions including continued uncertainty related to Brexit.

"The company is actively engaged in tackling the challenges it currently faces and will continue to seek to maximise its revenue streams," the company added. 

INM is due to release its results for 2017 in March.