United Airlines is considering creating a high-density Boeing 777 subfleet with 10 seats across--rather than nine--in regular economy class and a smaller than usual business class cabin, Aviation Week has learned.

The new configuration would allow United to install 364 seats on each aircraft, nearly 100 more than the airline has on many of its three-class 777s, a person familiar with the matter said.

United would retain nine seats across in premium economy, the source said, mimicking what American Airlines has done with its new Boeing 777-300ERs. Ten seats across in the regular economy section has quickly become the standard for new deliveries, with roughly 70% of new 777s now being delivered by Boeing with that configuration.

The plan under consideration calls for United to install 28 flat-bed seats in business class, 98 in premium economy and 238 in economy, airline documents show.

Internally, United is calling the new configuration the 77G. It is not clear how many 777s would be retrofitted, but the source said the aircraft would come from airline's United subsidiary -- rather than Continental -- and would be limited to aircraft with lower maximum takeoff weights.

United essentially has two versions of this aircraft. One is a three-class aircraft with 266 seats often deployed on short routes between the East Coast and Europe. The other is a two-class aircraft used on Hawaii routes. That subfleet was recently updated and the aircraft already have a relatively dense configuration.

"We evaluate lots of options across our fleet and haven’t made any further announcements specific to the 777 fleet,” a United spokesman said in an email. He declined to comment further.

United operates 74 777s, all of them -200s.