UPDATE 2-Boeing 2nd-qtr profit, cash top estimates; raises 2017 forecast again

again@ (Adds detail and analyst comment)

NEW YORK, July 26 (Reuters) - Boeing Co posted second-quarter profit and cash growth that beat analysts' estimates on Wednesday, even though sales were less than expected, sending shares up sharply.

The world's biggest plane maker is cutting costs by streamlining production of new 737 MAX models and finishing development of other new planes. Rising profitability of its 787 Dreamliner contributed about $530 million in cash in the quarter.

Boeing shares jumped nearly 4 percent at $220.65 in premarket trading. The stock has soared 37 percent this year.

Analysts focused on Boeing's abundant cash from operations, which at nearly $5 billion in the quarter was roughly double estimates of about $2.5 billion.

"Monster cash flow," said analyst Robert Stallard at Vertical Research. The results were "about as close to perfect as it gets from Boeing," he added.

Military aircraft sales fell 4 percent to $6.8 billion, but profit jumped 50 percent and margins widened 4.6 percentage points.

The extra cash allowed Boeing to add $1.5 billion to its operating cash flow forecast for the year, raising it to about $12.25 billion. Boeing will increase share buybacks this year by $3.5 billion, to about $10 billion. And it will make $3.5 billion in additional pension contributions this year to reduce future costs.

Boeing said it will cut full-year capital expenditure by $300 million, but that was expected since the company has made most of the big investments in its 777X wing factory and the 737 MAX and 787-10 programs, said analyst Richard Aboulafia at Teal Group.

The company lifted its full-year forecast for core earnings, which exclude some pension costs, by 75 cents to between $11.10 and $11.30 a share, its second upward revision this year.

Boeing swung to a profit of $1.76 billion, or $2.89 per share, in the second quarter, from a loss of $234 million, or 37 cents per share, a year earlier.

Last year's results included more than $2 billion in charges related to the 787, 747 and KC-46 tanker aircraft programs.

Core earnings, which excluded some pension and other costs, were $2.55 per share in the quarter.

Revenue fell 8.1 percent to $22.74 billion.

Analysts expected core earnings of $2.30 per share on revenue of $23 billion, according to Thomson Reuters I/B/E/S. (Reporting by Alwyn Scott in New York and Ankit Ajmera in Bengaluru; Editing by Saumyadeb Chakrabarty and Jeffrey Benkoe)