March 20 (Reuters) - Boeing ( BA ) has decided to keep

737 jet production below 38 per month and will only accept a

fully conforming fuselage from supplier Spirit AeroSystems ( SPR )

, CFO Brian West told analysts on Wednesday.

Shares of the planemaker fell 2.8% in premarket trading.

Manufacturing quality at both Boeing ( BA ) and the supplier are

facing increased scrutiny following a Jan. 5 incident in which a

door plug blew off a 737 Max 9 plane mid-flight.

West told a Bank of America conference that the

company's cash burn in the first quarter will be somewhere

between $4 billion and $4.5 billion, "higher than we originally

planned back in January."

The cash burn is due to a combination of lower

deliveries, lower volume at its commercial division along with

some working capital pressures.

(Reporting By Abhijith Ganaparavam in Bengaluru and Allison

Lampert in Montreal; Editing by Anil D'Silva)