NordStar raised its bid after a competing, unsolicited bid was received from a private investor group on Thursday, offering 14% more than NordStar's original bid, Torstar said.

Torstar, the publisher of the Toronto Star, Canada's largest daily newspaper, as well as various regional and community newspapers, said it turned down the unsolicited offer after its board of directors determined it would not be able to constitute a "Superior Proposal" under the NordStar Agreement.

Torstar did not identify the group making the unsolicited bid.

The Globe and Mail reported on Wednesday that Matthew Proud, chief executive of software firm Dye & Durham Corp, and his brother Tyler Proud were proposing to offer about $58 million for Torstar.

Torstar said its board recommends that shareholders approve NordStar's amended offer at the special meeting on July 21.

(Reporting by Aishwarya Nair in Bengaluru; Editing by Leslie Adler)