(Reuters) - Newspaper publisher Johnston Press Plc (>> Johnston Press plc) said on Wednesday the requisition notice from its top shareholder Custos Group seeking a general meeting was "invalid", but if it gets a valid requisition it would be put to shareholders.

A source close to Johnston Press told Reuters the letter was invalid because it had been signed by a wrong person.

Activist investor Custos Group, which owns about 20 percent of JPR and run by Christen Ager-Hanssen, on Tuesday sought a shareholder meeting to oust interim Chairman Camilla Rhodes and Michael Butterworth as directors.

Ager-Hanssen told Reuters on Tuesday that Custos would push for the appointment of Scotland's former nationalist first minister Alex Salmond as the publisher's chairman.

JPR publishes the Scotsman newspaper that opposed independence for Scotland in the 2014 vote.

The newspaper industry has been hit by the migration of advertisers to online platforms, forcing print publishers, such as Trinity Mirror (>> Trinity Mirror plc) and Daily Mail and General Trust (>> Daily Mail and General Trust) to cut costs drastically.

Last week, shareholder Crystal Amber Fund (>> Crystal Amber Fund Limited) cut its stake in Johnston Press to 10.48 percent from 18.15 percent.

(Reporting by Arathy S Nair and Sanjeeban Sarkar in Bengaluru; Editing by Gopakumar Warrier)