Liberty Global's Grenada unit Flow is suing both the island's telecoms regulator NTRC and the regional body, the Eastern Caribbean Telecommunications Authority (ECTEL).
Flow claims to have been discriminated against in the process that led to rival Digicel obtaining a license to operate 4G mobile networks in the country, according to media reports.
Both companies participated in the process but only Digicel obtained the license, local newspaper Now Grenada quoted public utility minister Gregory Bowen as saying.
Digicel reached an amicable solution with a smaller company about the use of the 700MHz band.
The license allows Digicel to launch a high-speed connectivity service in St. Lucia, Grenada and more recently in Saint Vincent and the Grenadines.