PRISA did not specify how much Herrero and his unidentified partners offered for the media assets, although it said PRISA shareholders could keep stakes in the new media company.

News website El Confidencial and financial newspaper Expansion had reported Herrero, who owns radio station Kiss FM, and Spanish partners planned to offer more than 200 million euros ($236 million) in cash to buy PRISA's newspapers and its radio and TV stations.

Following the reports, the stock market regulator suspended trading of PRISA shares on Thursday morning. The share price jumped nearly 15% when trading resumed after PRISA confirmed it had received a bid.

With net debt of 1.1 billion euros at the end of September, PRISA is suffering from dwindling spending on traditional media advertising, exacerbated by the coronavirus pandemic.

PRISA, with a market capitalisation of about 510 million euros, also owns Cadena Ser radio station and Cinco Dias financial newspaper.

After restructuring its debt, PRISA announced last month the sale of the Spanish division of its education editorial group Santillana to Finnish group Sanoma Corporation for 465 million euros.

PRISA's main shareholders are activist fund Amber Capital with 29.84%, HSBC with 9% and Santander and Mexican billionaire Carlos Slim's Grupo Carso, both with around 4%.

Spanish telecom firm Telefonica has whittled down its stake in Prisa to 9.4% from the 13% it owned in 2016. A source familiar with the matter said the telecoms group wanted to sell its stake, but has made clear it would not be willing to do so at a rock-bottom price.

PRISA has lost half of its market value this year.

In the first nine months of the year, PRISA's net loss widened to 209 million euros from 110 million euros in the same period a year ago. Its shares closed at 0.719 euros on Wednesday.

(Reporting by Emma Pinedo and Jose Elias Rodriguez, additional reporting by Belen Carreño, Isla Binnie; Writing by Inti Landauro; Editing by Ingrid Melander)

By Emma Pinedo and Inti Landauro