NEW YORK, June 14 (Reuters) - A New York real-estate firm cannot be sued over comments posted on its blog accusing a chief real-estate rival of being anti-Semitic and abusive, New York's highest court ruled Tuesday.

In a 4-3 ruling, the Court of Appeals held that the Communications Decency Act shields the Real Estate Group of New York Inc., or TREGNY, from liability for defamation and unfair competition against Ardor Realty Corp, because TREGNY was the blog's administrator, not the author of the comments in question.

"Creating an open forum for third-parties to post content -- including negative commentary -- is at the core of what section 230 protects," Judge Carmen Ciparick wrote for the majority. She was joined by Judges Victoria Graffeo, Susan Read and Robert Smith.

Section 230 of the Act shields internet service providers and users from liability for content created by a third party.

In dissent, Chief Judge Jonathan Lippman argued that because the defendants had drawn additional attention the comments by republishing them in a separate blog post, accompanied by an allegedly defamatory original illustration, the company could indeed be held liable under the CDA.

"While I do not dispute the adoption of a broad approach to immunity for online service providers under the CDA, an interpretation that immunizes a business's complicity in defaming a direct competitor takes us so far afield from the purpose of the CDA as to make it unrecognizable," Lippman wrote. His dissent was joined by Judges Eugene Pigott and Theodore Jones.

ANONYMOUS COMMENTS 

The case stems from a March 2008 lawsuit filed by Christakis Shiamili, president and CEO of Ardor, against TREGNY, its chief operating officer Daniel Baum, and Ryan McCann, the moderator of a now-defunct blog operated by TREGNY.

According to the complaint, an anonymous user posted a series of ugly comments to the blog accusing Shiamili of mistreating his agents, making anti-Semitic and racist remarks and abusing his wife, among other allegations.

McCann moved one of the comments to a separate post, adding his own commentary: "and now it's time for your weekly dose of hate ...". According to the lawsuit, McCann also posted a picture of Jesus Christ with Shiamili's face and the caption, "Chris Shiamili: King of the Token Jews," referencing an allegedly anti-Semitic remark cited by the anonymous commenter.

The trial court denied TREGNY's motion to dismiss the suit, concluding that more evidence was needed to determine what the defendants' roles were in developing the site's content. On appeal, the Appellate Division, First Department, reversed and dismissed the complaint.

Jonathan Shapiro, an attorney with The Shapiro Firm representing Shiamili, said he was disappointed with the ruling.

"We think that the dissent and the chief judge certainly got it right, but we'll have to live with the decision," Shapiro said.

An attorney for TREGNY and its employees, Joseph D'Ambrosio of Ford Marrin Esposito Witmeyer & Gleser, said his clients were pleased with the ruling.

The case is Shiamili v. The Real Estate Group of New York Inc. et al, in the New York Court of Appeals, no. 105.

For Shiamili: Jonathan Shapiro of The Shapiro Firm.

For TREGNY et al: Joseph D'Ambrosio of Ford Marrin Esposito Witmeyer & Gleser.

(Reporting by Jessica Dye)