PITTSBURGH - BOEING, which is ramping up airplane production after a costly strike, said on Thursday it was delaying the delivery of 737 jetliners and planning to inspect some already in service to replace parts that lacked a required anti-corrosion coating.

The uncoated nutplates, small fastening devices used to attach bundles of wires and other items to the inside of 737 fuselages, had been used since August 2007, said Ms Vicki Ray, a company spokesman.

Boeing delivered 394 of the planes between then and October of this year, according to Chicago-based Boeing's Web site.

The problematic parts, which lack a cadmium coating that would help prevent corrosion on adjoining aluminum parts, do not pose an immediate flight safety risk, she said. Thousands of nutplates are used on each 737.

Boeing, which ranks as the world's second-largest commercial airplane maker after Europe's Airbus, has been inspecting 737s at its commercial aircraft plants near Seattle, though production of the planes has not resumed since an eight-week strike by assembly workers ended earlier this month.

Boeing was notified about the problem by a Wichita, Kansas, company that builds wing and fuselage components for nearly every Boeing commercial aircraft, Spirit AeroSystems.

Spirit, a former Boeing subsidiary, got the bad nutplates from one of about three suppliers of the parts, said Mr Ken Evans, a Spirit spokesman.

'We're replacing them as we find them', Boeing's Ray said.

'Also to be addressed is the in-service fleet, and we're still working on a plan for that'.

Mr Evans, the Spirit spokesman, said his company discovered the problem in August. The bad nutplates came from a Boeing-approved supplier, he said.

'Our re-work is going very well', he said. 'We feel pretty good about it'. -- AP