A Miami-based technology holding company sent a cease-and-desist letter to Snap Inc. over Snapchat’s Geofilters feature, claiming the app infringes a patent it owns that the U.S. Patent and Trademark Office has approved for issuance. Snap waved off the claims as “groundless.”

Snapchat’s Geofilters, introduced in 2014, let users overlay location-based text and stickers in their posts and messages based on their location. The company that has taken legal action against Snap over the feature is United American Corp., which alleges Snapchat violates its patent, “User Content Sharing System and Method With Location-Based External Content Integration.” On Oct. 3, the USPTO issued an allowance for the patent (U.S. Patent Application No. 15/240,515), indicating it believes it qualifies for patent protection.

Snap, asked to comment, said in a statement: “We are aware of their letter, which is another ploy in their groundless claims over an invalid patent.”

Shares of Snap were down 1.4% in afternoon trading Thursday.

UnitedCorp obtained rights to the patent after acquiring iFramed Canada in June, in a deal with Vancouver-based Investel Capital Corp. under which Investel became the largest single shareholder of UnitedCorp.

The patent covers a mobile content-sharing application that can acquire and share new user images or videos and let users select locally sourced external content — based on their location — to be integrated within their own content before sharing. Investel was granted a Canadian patent for the method in June 2016 and two months later sued Snap for patent infringement in the Federal Court of Canada.

“We have tried to work on a good-faith basis with Snap since August 2016 to resolve the matter,” UnitedCorp president Benoît Laliberté, who is named as one of the inventors of the iFrame patent, said in a statement. “Unfortunately Snap has ceased to engage in discussions with us and instead has elected to rely on legal delay tactics in the Canadian proceedings.”

In addition to sending Snap a cease-and-desist notice, UnitedCorp said it has begun notifying companies that have used Snapchat Geofilters — including the Walt Disney Co., Taco Bell and Starbucks — about the legal claims.

UnitedCorp said it “has not yet completed a full review of other social-media applications,” but that it believes others may also be infringing the patent in question. The company claimed the iFramed patent portfolio has been appraised by patent-analysis firm TechInsights to be worth about $1 billion.

The iFramed app, available for iOS and Android, lets users post pictures and videos with geolocation-based sponsored overlays to Facebook, Instagram, Twitter and YouTube.