Aer Arann did indeed operate an IOM-LTN service. They also dabbled with LPL and MAN from the IOM, in competition with Euromanx:
Aer Arrann Launches Twice Daily LTN-IOM Service. - Airliners.net
BA Connect (if I remember rightly), used to operate LGW LTN LGW LGW with the 146, then dropped the LTN and replaced it with another LGW.
http://www.pprune.org/airlines-airpo...connect-5.html