Two Asian carriers have opted to install blended winglets on their Boeing 737 fleet, under agreements covering a total of 90 aircraft.
China Southern Airlines has committed to the winglets for 55 737s to be delivered between 2011 and 2015.
Winglet supplier Aviation Partners Boeing says the deal is its largest order from China.
Malaysia Airlines is also fitting the winglets to 35 737-800s that it is taking from the US airframer.
The first aircraft will be delivered this year, says Aviation Partners Boeing, and continue to 2013. Malaysia Airlines has experience with winglets on a "small fleet" of leased 737-800s, adds the firm, and this "led to the fleet-wide investment decision".
Aviation Partners Boeing claims the winglets can provide up to a 6t weight-capability improvement during take-off at hot and high airports.