Airbus has increased the standard number of seats in the brochure for its A380 superjumbo to 544, the company said last month.
The increase from the previous layout of 525 seats relies on a denser cabin configuration using 11 seats in each economy class row instead of the current 10.
Airbus says this can be achieved while maintaining 18-inch-wide (45.7cm) seats by better using the double-decker's space, but it remains unclear how passengers will respond.
"We have updated our A380 standard cabin layout to reflect the latest cabin innovations and trends, which have evolved since the A380 first entered service," a spokeswoman said.
The move comes as Airbus steps up efforts to boost sales of the plane, which has not found an airline customer since 2013.
The chief executive of Amedeo, a leasing company that ordered 20 planes and has a marketing partnership with Airbus, said in an interview published earlier that efficient formats up to around 600 seats held a key to finding new customers.
He also urged CEOs not to let computer models blind them to the way marketing can stimulate more traffic.
Planemakers routinely juggle their published seat counts to try to gain a marketing edge in the fiercely competitive jet industry. Actual layouts depend on the airline.
A higher seat count looks more appealing when examining costs per seat, a key benchmark. Top customer Emirates has also said many airlines are not using the A380 space effectively.
Boeing's 747-8i passenger plane officially carries 467 people. Both planemakers say their own models have more seats than the other side claims and that their rival has fewer seats.
The official seat count does, however, give a broad idea of the way planemakers want to market their jets.
The A380 has been reinvented several times, reflecting the prevailing industry mood, since it was launched in 2000.
It originally boasted 555 passengers at 10 seats abreast on the main deck "in greater comfort than ever before".
In May 2007, Airbus reduced this to 525 seats, saying the standards used for premium seating when it was being designed in the 1990s had not kept up with passengers' demands.
It has now rebranded the jet as a 544-seater based on four classes and 11 seats in economy, reflecting a post-recession trend towards denser layouts across the airline industry.