WASHINGTON (AFP) - Boeing on Friday said it would cut production of its 747-8 jumbo aircraft for a second time this year, citing weaker demand for big aircraft.

The Chicago-based aerospace giant said 747-8 production rate would be reduced from 1.75 airplanes per month to 1.5 airplanes per month "because of lower market demand for large passenger and freighter airplanes."

"This production adjustment better aligns us with near-term demand while stabilizing our production flow, and better positions the program to offer the 747-8's compelling economics and performance when the market recovers," Mr Eric Lindblad, vice president and general manager of the 747 programme, said in a statement.

Mr Lindblad said the output adjustment "doesn't change our confidence in the 747-8 or our commitment to the programme." In April Boeing cut the production rate for the four-engine jumbo jet from two airplanes to 1.75 airplanes per month, again giving lower demand as the reason.

Boeing predicted on Friday that long-term average growth in the air cargo market would begin returning in 2014, and put global demand for large airplanes over the next 20 years at 760 units, valued at US$280 billion (S$348 billion).

The list price for a 747-8 twin-aisle passenger plane is US$356.9 million, while the 747-8 Freighter is valued at US$357.5 million.

Boeing said it has 107 orders for passenger and cargo versions of the jumbo jet to date, of which 56 have been delivered. For 2013 through October 15, Boeing booked a net five 747 orders, according to its website.

Deliveries at the new production rate were expected to begin in early 2014.

The reduced rate was not expected to have a significant financial impact, it said.

Shares in Dow member Boeing were up 0.3 per cent at $122.70 in afternoon trade on the New York Stock Exchange.