Boeing Co. said it favors an all-new 737 single-aisle jet over an upgrade of the existing version and is studying whether to add more seats to help reduce carbon emissions per passenger

“Our job is to improve the operating efficiency,” Jim Albaugh, chief executive officer of Boeing Commercial Airplanes, said yesterday after the company reported earnings. “Re- engining is one way to do it, but quite frankly the business case for re-engining is not as compelling as we’d like to see.”

Boeing and European rival Airbus SAS are weighing the merits of an upgrade for their best-selling planes after pushing back plans to develop new models, saying engine technologies aren’t ripe. Boeing will decide by early next year and Airbus has promised a decision within two months.

http://www.bloomberg.com/news/2010-10-21/boeing-favors-all-new-737-with-more-seats-to-reduce-emissions.html