UPDATE 2-Spirit AeroSystems' shares soar on Boeing pricing deal

* Q2 profit, revenue beat Street

* Raises 2017 adj. EPS, cash flow forecasts

* Shares rise 11.5 pct premarket (Adds background, details)

Aug 2 (Reuters) - Spirit AeroSystems Holdings Inc reached a tentative agreement with Boeing on pricing terms as part of a long-pending supply deal related to aircraft such as the 787 Dreamliner, sending its shares up 11.5 percent premarket.

The aircraft parts maker on Wednesday said it took a $353 million charge, in the second quarter ended June 29, for adjusting prices of certain parts of Boeing's 787 aircraft.

The deal comes nearly a year after Spirit Aero took a charge, when it signed a similar agreement with Airbus SE for its A350 XWB aircraft, a competitor to Boeing's Dreamliner.

Boeing, Spirit Aero's biggest customer, and European rival Airbus have been pressing suppliers to cut prices on aircraft parts, as they seek to stay competitive amid burgeoning demand from airlines for more capable planes at lower prices.

Spirit Aero has been in talks with Boeing related to prices for parts, including fuselage sections, components that connect engines to wings and wing structures for the 787-9 and 787-10 Dreamliners.

Pricing for the initial configuration of Boeing's wide-body 787-8 aircraft has been established through 2021, the company had disclosed in a regulatory filing. (http://bit.ly/2w5SiJS)

However, Spirit Aero and Boeing were yet to determine initial prices for parts of the 787-9 and 787-10.

Spirit Aero said on Wednesday the deal is expected to complete in the third quarter of 2017 and would establish prices for the 787 aircraft through 2022.

The agreement will also address "open commercial issues" on a range of Boeing programs, including the single-aisle 737 Max aircraft.

The deal reduces uncertainty that has long existed with Boeing and preserves Spirit Aero's ability to meet long-term cash flow goals, Chief Executive Tom Gentile said.

Spirit Aero raised its full-year adjusted earnings per share forecast to $5.00 to $5.25 from $4.60 to $4.85.

The company also increased its free cash flow forecast by $50 million to between $500 million and $550 million.

Spirit Aero posted a loss of $56.8 million, or 48 cents per share, in the quarter, compared with a profit of $44.8 million, or 35 cents per share, a year earlier.

On an adjusted basis, Spirit Aero earned $1.57 per share.

Total revenue was little changed at $1.83 billion.

Analysts on average expected earnings of $1.21 per share and revenue of $1.75 billion, according to Thomson Reuters I/B/E/S.

The company's stock rose 11.5 percent to $68 in trading before the bell. (Reporting by Ankit Ajmera in Bengaluru; Editing by Martina D'Couto)