Shareholders in US carrier Horizon Lines have launched a law suit against the company claiming it "misled investors" about its profitability and "artificially inflated its share price". The complaint alleges that between 2 March 2007 and 25 April 2008, the Jones Act carrier made "false and misleading statements or failed to disclose material adverse facts" in relation to its alleged involvement in price fixing on freight services to Puerto Rico. By allegedly illegally manipulating the prices for Puerto Rico freight services (in violation of federal antitrust laws), Horizon fraudulently misled investors as to its own profitability and inflated its own stock price." In April, Horizon Lines admitted federal agents raided its offices and launched an investigation of pricing practices of ocean carriers operating in the Puerto Rico trade.

Following this, six employees involved in the Puerto Rico trade lane were placed on administrative leave and two of the six resigned subsequently.The investors claimed the shipping line "shocked" them further when it announced in its firstquarter results it was revising the company's earnings guidance for 2008 downwards, causing its share price to decline. Subsequently, the US Department of Justice announced three Horizon Line executives had agreed to plead guilty for their roles in the price fixing scandal. The individuals, Gabriel Serra, Kevin Gill and Gregory Glova, were former Horizon Lines managers and agreed to plead guilty, serve time in jail, pay criminal fines and co-operate fully with the anti-trust investigation.