"Having obtained updated valuations of its legal advisors, (RCS) has decided that the conditions for the recording of provisions for risks do not exist," the company said in its first-half results statement.
Last month, Blackstone requested a court in New York to merge two lawsuits related to the disputed property sale, while seeking damages for more than $600 million from the Italian company.
RCS said on Friday the damage request was "based on general and unsubstantiated allegations".
The publisher of influential daily Corriere della Sera launched arbitration proceedings in late 2018 to nullify the 2013 sale to Blackstone, saying the U.S. investment firm had paid too low a price at a time when RCS faced financial difficulties.
Blackstone, which paid 120 million euros ($142.5 million) for the offices, in turn accused RCS of falsely claiming it still owns the building and of improperly blocking its sale to Germany's Allianz but the case in the U.S. was suspended until the arbitration outcome.
In May, a Milan arbitral tribunal ruled in favour of Blackstone, rejecting all claims by RCS.
($1 = 0.8418 euros)
(Reporting by Claudia Cristoferi; Editing by Mike Harrison)