it has 2 or 3
Their is a nine volume one that covers the first anime series and has most of the funny stories form fumofu. Their was another one that was like 4 volumes and was all about some original side story that didn't look too good, plus i didn't like the art style where everyone was chibi.
Also, full metal panic: sigma, covers TSR and is ongoing after those events, to my knowledge it is suposed to go to the end of the light novels when they finish. It is currently being scanlated by moob, they do a good job but are slow as fuck.