In September 2002, Gulfstream announced the improved G150, based on the G100. This last variant features a wider (12 in) and longer fuselage (16 in aft of rear pressure bulkhead) updated avionics and an increase in maximum takeoff weight (MTOW) to 26,100 pounds (11,839 kg) compared to the G100's MTOW of 24,650 pounds (11,181 kg).
It has been certified for the steeper-than-normal approach path required to land at London City Airport. Production of the G100 was discontinued following certification of the G150. IAI continued to manufacture G150s in Israel and the completed airframes were then flown to the U.S. for interior outfitting.
In September 2016, Gulfstream announced that production would be stopped, with delivery of the final aircraft due in mid-2017.