Fla. company files antitrust suit against UPS.

Amid the euphoria of United Parcel Service's initial public offering Wednesday, investors likely weren't aware of an antitrust lawsuit that has been filed against the company by an upstart Fort Lauderdale competitor.

Logistics company Link Express, which launched two years ago with the heady goal of providing a nationwide alternative to UPS, began shipping packages in earnest this March through its wholly owned subsidiary Package Express. While UPS delivers packages through its own fleet of trucks and planes, Link relies heavily on competitors to ship packages outside of South Florida.

Problems apparently arose after UPS realized that Package Express was …