Boeing ( BA) cut its first-quarter earnings outlook Thursday, reflecting reduced widebody plane production.

The aircraft manufacturer says it will cut monthly production of the 777 from seven to five airplanes a month beginning in June 2010, and will delay previously announced plans to modestly increase production of the 747-8 and the 767.

Additionally, Boeing said the weak economy "has contributed to significant declines in the escalation indices that affect forecasted pricing for commercial airplanes already ordered."

The production cuts and unfavorable price escalation are expected to reduce first-quarter earnings by about 38 cents a share, the company said. The reduction includes a 31-cent charge for the 747 program, which was already expected to show a loss, as well as a 7-cent reduction due to lower margins on deliveries of other aircraft.

Analysts surveyed by Thomson Reuters had been estimating first quarter earnings of $1.20 a share.

The cuts were announced after the market closed. In after-hours trading, Boeing shares were down $1.20 to $37.95.

"These are extremely difficult economic times for our customers," said Scott Carson, CEO of Boeing Commercial Airplanes, in a prepared statement. "It's necessary to adjust our production plans to align supply with these tough market conditions."

Boeing said the production rate decisions announced Thursday reflect delivery deferrals requested by customers: the company said no orders for 747s, 767s or 777s have been canceled and "no change is being made at this time to the 737 production rate."