Jan. 1, 2014, marked the 20-year anniversary of the North American Free Trade Agreement, or NAFTA. While economists still debate the success of the agreement, most people would agree that transport companies benefited greatly from the increased trade. While a great deal of the trade between the NAFTA countries is done by truck, trade with companies in Europe and Asia is done mainly by boat. Therefore, an increase in trade with overseas countries could spur demand for shipping.

The shipping companies
Three maritime companies that depend on international trade are Star Bulk Carriers (SBLK -1.96%), Diana Shipping (DSX 0.35%), and Navios Maritime Partners (NYSE: NMM).

Star Bulk owns 13 ships, with an average age of 10.7 years.  While Star Bulk has had net losses every year from 2009 to 2012, it is improving its financial situation. As of Sept. 30, 2013, its cash was $84 million compared to $31 million one year prior, and its debt was $194 million, compared to $224 million a year before. This was before its purchase of five more ships at a cost of $215 million. Star Bulk is attempting to grow its fleet while managing its debt, not an easy task. If it can pull this off, it may start turning a profit. Watch for its 2013 annual report for more information.

(DSX 0.35%)

Navios Maritime Partners (NYSE: NMM) operates 30  ships with an average age of six years. This company had net income of $95 million for 2013, compared to $65 million in 2012. On Sept. 30, 2013, it held $198 million in cash and a total debt of $345 million. With its large fleet of ships and cash reserves, it is well equipped to take advantage of an increase in demand for shipping.

The trade agreement
One thing that might increase demand for shipping is a potential trade agreement between the U.S. and Europe. The Transatlantic Trade and Investment Partnership, or TTIP, would eliminate tariffs between the U.S. and Europe, which currently stand at 5.2% for Europe and 3.5% for the U.S. According to the U.S. Chamber of Commerce, just removing the tariffs would increase U.S. economic growth by $180 billion over five years. The real benefit, however, would come from streamlining regulations, which differ between the two continents. The agreement could boost the economies of the E.U. and U.S. by an estimated $100 billion annually. The U.S. and European Union hope to have the agreement finalized by the end of this year.

The risks
Even if the agreement is finalized, there is no guarantee that it would lead to an increase in demand for shipping. An economic slowdown in China, for example, would hurt shipping, as would a slowdown in Europe. While it is impossible to predict how the shipping industry will do in the future, a new trade agreement between the U.S. and the E.U. has the potential to help it grow.