Surging revenues from the super-heated commercial aircraft market helped Boeing posted a 61% year-to-year increase in net income for the third quarter.

Boeing’s third quarter net income rose to nearly $1.5 billion on sales of $16.5 billion across the company, which reflects a 12% improvement in revenues from the same period a year ago.

Driving Boeing’s improved results is the commercial aircraft sector. Third-quarter revenues jumped 23% from 2006 to $8.2 billion, with the number of aircraft delivered rising from 100 to 109 in 2007.

However, a six-month delay for the 787 announced a week ago forced Boeing to downgrade its financial outlook for 2008.

Boeing’s revenue guidance for 2008 was adjusted from between $71 billion to $72 billion to between $67.5 billion to $68.5 billion.

Cash flow guidance for 2008, meanwhile, was slashed from $7 billion to $3 billion. Projected aircraft deliveries next year declined from between 515 to 520 to between 480 to 490.

Further, spending on research and development will not decline as fast as expected. Boeing now expects to spend $3.7 billion on research and development in 2007 and between $3.2 to $3.4 billion in 2008. Previously, Boeing expected R&D costs to drop to $2.8 billion to $3 billion next year.

The company attributed half of the R&D costs to the 787 delay and the other half to extra spending on the international tanker and a request by a military customer to assign certain proposal costs to R&D instead of other accounts.