Sept 12 (Reuters) - S&P Global Ratings said on Thursday

if Boeing ( BA ) faces an extended worker strike, it could delay

the planemaker's recovery and hurt its overall rating.

Boeing's ( BA ) U.S. West Coast factory workers started voting on

Thursday on a much-criticized new contract and a possible

strike, piling pressure on the company as it wrestles with

chronic production delays and mounting debt.

A potential strike starting on Friday would be a big early

blow to Boeing's ( BA ) newly appointed CEO Kelly Ortberg, who was

brought on last month to restore faith in the planemaker after a

door panel blew off a near-new 737 MAX jet in mid-air in

January.

"A shorter strike (along the lines of the situation at

Spirit Aero last summer where union leadership accepted the

company's offer and membership rejected it) would probably be

manageable for the company and the rating," said Ben Tsocanos,

aerospace director, S&P Global Ratings.

Tsocanos said the strike could pressure Boeing's ( BA ) ability to

reach its target of increasing MAX jet production to 38 planes a

month by the end of the year.