Yes, you may authorize an employee to travel by other than coach-class on common carriers or other than lowest first-class on ships as long as the:
(a)
Non-Federal source makes full payment for such transportation services in advance of travel; and
(b)
Transportation accommodations furnished are comparable in value to those offered to, or purchased by other similarly situated meeting attendees; and
Code of Federal Regulations
[FTR Amdt. 2009-06, 74 FR 55151, Oct. 27, 2009]