In a letter quoted by Polish state media, Mark Dekan of the Ringier Axel Springer Media AG reportedly criticised Poland's isolated stance at a recent EU summit, saying it cost Poland its reputation as a partner and was a defeat for Poland's ruling conservative party leader, Jaroslaw Kaczynski.
The company owns a tabloid, a magazine and some other media in Poland.
Poland's Foreign Ministry said the letter could be seen as undermining the independence of Polish media, while Deputy Prime Minister Piotr Glinski said work is underway on a new law that would curb media ownership by individual concerns, especially foreign ones.