BERLIN — President Recep Tayyip Erdogan of Turkey tried again to silence one of his German critics, but failed this time when a court denied his request on Tuesday to block an open letter by the head of one of Germany’s most powerful media companies expressing support for a comedian who lampooned the Turkish leader.

The court’s decision to refuse Mr. Erdogan an injunction against the letter by Mathias Döpfner, the chief executive of the media firm Axel Springer, is the latest round in a fight over free expression in Germany that began when the comedian, Jan Böhmermann, read on television a crude, satirical poem he has said was intended to insult Mr. Erdogan.

The Turkish president, who has jailed critics and cracked down on free speech in his own country, took the comedian’s bait: He seized upon a little-known German law, dating from 1871, to press charges against Mr. Böhmermann.

Although Chancellor Angela Merkel allowed the proceedings to go ahead, German citizens responded with outrage at what they saw as an attempt by a foreign leader to stifle freedom of expression in their country.