MadmanAtW
Knight
If you want to follow Greek mythology, how about using names derived from the Titans? Less known then the Olympian gods. Here are their names: Oceanos, Coeus, Crius, Hyperion, Iapetos, Theia, Rhea, Themis, Mnemosyne, Phoebe, Tethys, and Kronos. Plenty to give names to subparts of a main continent.
While I would usually never discourage someone from using Titanic names, being a huge fan of them, I will note that Titan names is the naming scheme used for Saturn's moons, and as such it seems unlikely that they would be "reused" for the continents in another solar system. :/ Granted, not all of the ones listed above have been used in our system.