The way to tell if/when the company is looking at another equity investment that leads to a JV is to look for language similar to the 2Q2015 report related to Aeroméxico.

Generally, it's an derivative contract for shares in the foreign company which can be converted upon JV contract closing. If the two companies cannot come to some sort of agreement that leads to a JV, Delta can cash out the derivative and walk away with their cash +/- the change in value of the underlying foreign security.

A simple and safe way to conduct a foreign transaction with an unknown outcome.