File Photo, protesters show the victory sign as they hold up placards with the letters of Poland s main private TV network TVN, a US-owned broadcaster, as they demonstrate in defence of media freedom in Warsaw.on August 10, 2021. AFP
"I am vetoing it," Duda said in a televised statement, following heavy criticism of the law from the European Union and the United States.
Polish lawmakers adopted the law earlier this month.
The law would have prevented companies from outside the European Economic Area from holding a controlling stake in Polish media companies.
That would have forced US group Discovery to sell its majority stake in TVN, one of Poland's biggest private TV networks.
TVN24 is its news channel.
The government had argued the law would protect Poland's media landscape from potentially hostile actors such as Russia.
Duda said he agreed with this principle, but that it should not be made to apply to existing business arrangements and investment treaties.
The US charge d'affaires in Warsaw, Bix Aliu, had called on Duda to veto the bill, saying Washington was "extremely disappointed" by the legislation.
"We expect President Duda to act in accordance with previous statements to use his leadership to protect free speech and business," Aliu said earlier.
European Commission spokesman Christian Wigand also said earlier that the proposed legislation would pose "severe risks to media freedom and pluralism in Poland".
Thousands of Poles protested earlier this month outside the presidential palace in Warsaw against the law, with many in the crowd waving EU flags and chanting "Free media!".
Discovery had said the law "should alarm any enterprise investing in Poland and anyone who cares about democracy and freedom of the press".
Poland's ruling Law and Justice (PiS) party already controls public television broadcaster TVP, which has become a government mouthpiece, and much of the regional press.
Since PiS was elected to power in 2015, Poland has dropped 46 places in Reporters Without Borders World Press Freedom Index to reach the 64th position.
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