DALLAS — Southwest Airlines Co., facing a deadline today for settling a dispute with regulators over the use of unapproved parts, said yesterday the parts were installed on almost twice as many planes as it first believed.

The airline also has suspended the maintenance firm that got the parts from a subcontractor.

Southwest said yesterday it has replaced the unapproved parts in more than 25 planes but needs more time to find parts for the remaining jets and an extension to avoid a disruption in its service to its customers.

Without an extension, the Federal Aviation Administration could force the airline to ground some planes.

WALMART SITE ADDS OUTSIDE VENDORS

LITTLE ROCK, Ark. — Wal-Mart Stores Inc. has launched an addition to its online business that has outside retailers selling nearly 1 million new items through Walmart.com, a move that could help the world's largest retailer catch up in the online world.

The Walmart Marketplace has products from categories that include home, baby, toys, apparel, sporting goods and sports memorabilia.

The company said it picked the retailers — including eBags, CSN Stores and Pro Team — because they have large product assortments and solid customer service track records.

BOEING'S CARSON TO RETIRE AT YEAR'S END

CHICAGO — Boeing Co. said yesterday that Scott Carson will step down as head of the company's commercial airplane division and retire at the end of the year.

Boeing's commercial aircraft operation has struggled with sharply lower orders amid the global economic downturn.

It also has grappled with problems arising from its new 787, a next-generation aircraft that's been delayed five times. Boeing said last week the lightweight plane will fly for the first time by year's end.

BAKER HUGHES TO BUY BJ SERVICES

HOUSTON — Oilfield services company Baker Hughes Inc. said yesterday that it will buy BJ Services Co. in a cash-and-stock deal valued at $5.5 billion to diversify the services it offers and compete better in the industry.

Baker Hughes customers will get a one-stop shop for a variety of services. Notably BJ Services' pressure pumping business will go to Baker Hughes, which will help clients with unconventional gas and deepwater fields, said Chad Deaton, Baker Hughes chairman, president and chief executive officer.