Airbus rival Boeing has blamed a third-quarter net loss of $1.6 billion (£974 million) on rising production costs and poor market conditions.

The latest results reflect charges incurred to modify Boeing's 787 Dreamliner and the new updated version of its 747 jumbo jet.

The steeper-than-anticipated loss has led the company to cut its profit forecast for 2009.

Shares in the firm fell 2.4 per cent to $50.64 (£30.69) after the figures were announced.

The loss compares with a profit of $695 million (£421 million) made in the same period a year earlier.

The Chicago-based company has 840 orders for the 787, from 55 customers. Boeing delivered 113 aircraft during the third quarter, a 35 per cent increase from a year ago.