May 10 (Reuters) - The U.S. Food and Drug Administration has pushed back its decision on Moderna's respiratory syncytial virus (RSV) vaccine by more than two weeks to the end of this month due to some "administrative constraints", the company said on Friday.

The FDA's move prolongs the wait for Moderna's second approved product, but the company said it remains on track to be reviewed by a panel of advisers at the U.S. Centers for Disease Control and Prevention (CDC) on June 26 and 27.

The CDC panel is expected to vote on recommendations for the vaccine's use and the intended population at the meeting, and success there is necessary for commercial launch.

Cambridge, Massachusetts-based Moderna has been banking on its experimental shots to make up for vastly lower sales of its Spikevax COVID vaccine, its only marketed product, after the pandemic. (Reporting by Patrick Wingrove and Leroy Leo in Bengaluru; Editing by Shinjini Ganguli)