Andreas,
According to this link (search for Glazer):
http://www.airmuseum.ca/mag/exag0306.html
it would have been 69 squadron.
"Al Glazer and Eric Cameron. Al Glazer trained as a Radar Technical Officer and went to Malta in Jan. 1941 in a Sunderland with two technicians and primitive ASV Radar equipment. Mission, to equip 69 Squadron’s three Wellingtons with radar to help them in their night shipping strikes. Glazer learned navigation and earned one of the few RO half wings. He was awarded the DFC and Mentioned in Dispatches during two Op. tours. In addition to the Malta George Cross, Al was awarded the Canada 125th Anniversary Medal."
"Al Glazer developed special radar liaison between the Wellingtons and the Malta based submarines, whereby a Morse key hook up to the radar enabled the aircraft to send coded “blip” messages to submarines equipped with the Glazier-designed receiving aerials attached to their periscopes. After receiving the enemy convoy’s course and speed from the Wellingtons, the submarines could intercept and strike."
148 Squadron also had Wellingtons on Malta, but I think they operated as a night bombing unit. Maybe someone has more info on all of this.