The provisionally dubbed A380-Plus makeover would add 40-50 seats to increase the standard interior's capacity to more than 600 seats which would help airlines reduce their costs per passenger.
To make room for those extra passengers, the A380 would do away with the double staircase at the front of the plane in favour of something more compact.
The narrower spiral staircase at the back would also be modified.
Airbus officials declined to comment on the plans, which have yet to be finalised and approved.
"Airbus is always studying opportunities to improve our aircraft," a spokesman said.
The sweeping staircase is one of the first features passengers see on boarding an A380 and captured attention when the A380 was first rolled out as a 'cruise ship of the skies' in 2005.
However, sales have fallen in recent years due to advances in smaller twin-engined jets, which cost less to fly and maintain.
To help on the A380, the addition of vertical wingtips, more typically seen on smaller narrow-body jets, would cut fuel consumption by reducing drag.
The sources, speaking on condition of anonymity, said the makeover would improve fuel efficiency by around two percent.
They said the changes may also be available as retrofits to existing A380s, but that this had not yet been decided.
The design changes would add about three tonnes to the A380's maximum take-off weight, leaving more room for payload or fuel.