"We did not violate the law. This case appears to be an attempt to deprive Filipinos of the services of ABS-CBN," the broadcaster said in a statement.
- 'Better off selling' -
Advocates said the government move was the latest attack on press freedom under Duterte, who has already tangled with a top newspaper and a website.
"We must not allow the vindictiveness of one man, no matter how powerful, to run roughshod over the constitutionally guaranteed freedoms of the press," said the National Union of Journalists of the Philippines.
Journalist Maria Ressa faces years behind bars in a case that she and press advocates say was retaliation for the journalism of her website Rappler.
Rappler, which has published stories critical of Duterte's administration, is also battling a government closure effort.
Both Rappler and ABS-CBN stand accused of violating a constitutional ban on foreign ownership of mass media outlets. Both refute the allegations.
The solicitor general also accused ABS-CBN of launching a pay-per-view channel and extending its franchise to other entities without congressional approval.
Duterte taunted the network in a speech in December, telling the owners to sell it.
"ABS-CBN, your contract is about to expire. If I were you, you're better off selling it," Duterte said.
