UPDATE 1-Spirit AeroSystems chief operating officer to depart

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WASHINGTON, Nov 28 (Reuters) - Aerospace supplier Spirit AeroSystems on Tuesday announced the departure of Chief Operating Officer Samantha Marnick, who also oversaw the company's commercial aircraft business.

The leadership change at the Wichita, Kansas-based company follows the resignation of longtime CEO Tom Gentile in October after a series of expensive production defects and financial losses caused a 45% drop in shares since the beginning of the year.

Spirit, a major supplier of airplane structures, makes large portions of Boeing and Airbus airliners - including the entire fuselage of the Boeing 737 MAX.

Terry George will serve as interim senior vice president, leading site operations in Wichita and Tulsa, Oklahoma, including fabrication, operations engineering, tooling and facilities, the company said.

Program managers formerly under Marnick will report directly to CEO Patrick Shanahan, a former Boeing executive who has committed to lead Spirit for a year while finding a permanent chief executive.

(Reporting by Valerie Insinna; Editing by Will Dunham)