BRUSSELS - The European Union's executive on Thursday welcomed Poland's extension of broadcasting license for a news channel critical of the government but warned related discussions in the Polish parliament might still end up undercutting media freedom.

After long delays, Poland's broadcasting regulator on Wednesday extended the license for TVN24, which is owned by the U.S. Discovery.

The regulator, however, also called on the Polish parliament to bring more legal clarity into whether TVN24 had the right to continue operating.

Should the parliament tighten the current law - as advocated by some members of the ruling Law and Justice (PiS) party - Discovery might be force to sell more than a half of its media business in Poland estimated to be worth more than $1 billion.

The case has strained ties between Poland and the United States.

(Reporting by Gabriela Baczynska, editing by Robin Emmott) ((gabriela.baczynska@thomsonreuters.com; +32 2 287 68 39; Reuters Messaging: gabriela.baczynska.thomsonreuters.com@reuters.net))