As far as nano-UAVs, there are a growing number of products in the marketplace for the Marine Corps to choose from, said Phil Finnegan, an analyst with the Teal Group.

A Norwegian company, ProxDynamics, is offering a palm-sized miniature helicopter, the PD-100 T Black Hornet, which can fly with an electro-optical camera and thermal sensor provided by FLIR Systems Inc. for night operations. U.K. forces, and possibly U.S. Special Operations Command, have purchased some of the mini-copters, Finnegan said.

Nano-UAVs "definitely [are] a rapidly growing market. That being said, the [contract] value is nowhere near those of the larger systems," he added.

Analyst Richard Aboulafia of the Teal Group interpreted the Marine Corps' comment as putting pressure on Rolls. "When you're in a sole-source situation and you're not happy with the price of spares and durability of spares, the best way to put pressure on the contractor is to imply that there could be competition in the future," Aboulafia said. "If [Rolls] could somehow combine lower cost with higher performance, that might be something [the Marine Corps] would really want, but on the other hand, it's not clear that's what's going on here."