BRUSSELS, Sept 23 (Reuters) - The European Union"s executive said on Thursday that risks to media freedom in Poland persisted despite a decision by the Polish regulator to extend a broadcasting licence for TVN24, aU.S. Discovery-owned news channel critical of Warsaw. After long delays, the regulator on Wednesday extended the license for TVN24 but also asked the Polish parliament to provide more legal clarity over whether TVN24 had the right to continue operating. read more A spokesman for the European Commission told a daily news briefing in Brussels the extension was a "positive development" but added: "We are also aware of a special resolution in this context, adopted yesterday, on the rules on granting the broadcasting concessions for TV and radio channels." "We will continue to monitor the developments very closely ... We expect (EU) member states to ensure that their policies and legislation do not have any negative impact on their commitment to ensure a free, independent and diverse media ecosystem." Should the parliament tighten the current law on foreign ownership of media broadcasting in Poland - as advocated by some members of the ruling Law and Justice (PiS) party - Discovery might need to sell more than half of its media businessesthere. Estimated to be worth more than $1 billion, they include more than a dozen TV channels, as well as an online video on-demand platform. The TVN group says it employs 4,200 people and posted a 2019 net profit of 540 million zlotys ($137 million). The TVN24 case has strained ties between Poland and the United States and deepened concerns voiced by Washington, the EU, rights groups and international watchdogs that PiS is undermining media freedoms as part of a broader backsliding on democracy that has also affected Polish courts and NGOs. ($1 = 3.9280 zlotys)