The iqta' system was a system of land grants in exchange for service; while it was originally not intended to be feudal (then again, what ruler intentionally sets up a feudal system if he's powerful enough to impose a more centralized, absolutist system?), but in the case of the Seljuk Empire, it increasingly resembled European lordships after the death of Malik Shah, the last of the strong, undisputed Seljuk sultans. Local emirs became essentially autonomous. At the Battle of Harran (1104) for instance, Jikirmish of Mosul and Sokmon bin Artuq of Mardin, two emirs who were nominally iqta'dars of the Seljuk Empire, collaborated to defeat the forces of the Principality of Antioch, but were unable to capitalize on their victory because they quarreled over the distribution of spoils. Legally, an iqta' was a little different from a French-style fief, but they had some practical similarities.

The Ottomans had a system of land-grants-for-service too (timar), but as far as I know, they were able to retain control over the distribution of grants and enforce the loyalty of the holders (timariots). As such, they avoided any kind of "feudal" system, and got their land-grant supported troops to be loyal to the sultan -- something which some previous Muslim states (such as the Seljuks) and Christian states (such as the Carolingians) had aspired to do, but not ultimately succeeded. Possibly they were more successful because their core army of court slaves (kapikulu) was sufficiently intimidating that timariots didn't stray too far from the sultan's will, or possibly because the timars were more limited in size.

There are other cases of Muslim states fracturing with local emirs effectively gaining autonomy, such as the breakup of the Abbasid caliphate, but it’s not clear to me that these really had any kind of “feudal” legal basis like the fief or iqta’, or whether it just involved local strongmen asserting autonomy in defiance of a centralized (albeit ineffectually centralized) state.

I'd add to /u/Maklodes that part of the problem seems to be that characterizing this connection between land and military service is something of a hot potato in the historical literature. Historians of the east describing the Iqta will be quick to point out the differences between the Iqta and European feudalism (e.g. the Iqta was a centralized system, non-hereditary in theory, was not part of a system of mutual obligations, was not based upon a relationship of conferring noble legitimacy, etc.) but from what I've read from European historians they are just as likely to punch holes in the "feudal" system and say it didn't exist in Europe either.

Another distinction would be that there were several types of Iqta conferred on the person in question (be they a local notable, member of the royal household, or a military commander). One type referred to money paid directly out of the treasury. The administrative iqta referred to appointment as governor of an administrative province without having ownership of the lands in question. There were also personal iqta, estates granted to an individual fully within his possession and to be passed on through inheritance. Then there was the military iqta, lands granted to a military commander either to profit from directly or to farm the taxes from indirectly. None of these categories is mutually exclusive and there was quite a lot of blending of type and bending of the theoretical rules as notables and military commanders tried to assert greater control on their lands.

A good source on this would be David Morgan's book "Medieval Persia, 1040-1797."

edit: profit not prophet.