The complaint, filed in a US district court in San Jose on Friday, centres on Gartner’s classification of ZL as a “niche” vendor in its Magic Quadrant reports.

District Court Judge Jeremy Fogel ruled in early November that Gartner’s reports consituted “non-actionable opinion” which could not be the basis of a libel suit, but ZL argues that Gartner presents its analysts’ opinions as being “based on a body of fact”.

ZL said in a statement that its amended complaint “clarifies” its contentions about the content of Gartner’s reports, and alleges an “inherent conflict of interest” because of the business Gartner conducts with many of the firms whom it reviews.

A spokesperson for Gartner told Research today: “We are aware that ZL Technologies has re-filed an amended complaint regarding its location in a Gartner Magic Quadrant even though its initial complaint was dismissed. We continue to consider ZL Technologies’ allegations to be completely without merit and intend to move to dismiss them again in the courts. We remain committed to providing our clients with independent research and advice about the products that we cover.”

ZL seeks an injunction as well as compensatory and punitive damages from Gartner.