It comes just weeks after Mr Justice Tugendhat reversed a gagging order slapped on the national media concerning the private life of former England captain John Terry, who was represented by Schillings.
It is understood that Schillings instructed 4-5 Gray’s Inn barrister Richard Spearman QC to act for Horlick.
McCrystal was represented by Taylor Wessing partner Niri Shan, who instructed 5 Raymond Buildings’ David Sherborne.
In May 2009, Mrs Justice Swift granted the injunction against McCrystal, who was considered a personal friend of Horlick, after it was claimed that he was about to go public on details about the fund manager’s private life.
Mr Justice Eady overturned the injunction in June but, according to sources, the tone of the injunction remained in place and McCrystal was the subject of private proceedings against him for damages.
Schillings could not be reached for comment, but in a statement issued to the national media the firm said Horlick would “discontinue proceedings” and was “happy to accept that he [McCrystal] did not divulge personal details”.
In addition, the statement issued an apology for the “misunderstanding” and said that that would be “reflected in the costs settlement”.
Earlier this week Schillings hit the headlines when it issued proceedings against the News of the World on behalf of Brad Pitt and Angelina Jolie after the tabloid refused to retract allegations that the couple had split.
The couple are reportedly suing the tabloid for libel as well as misuse of private information.