UPDATE 2-Boeing wins $4.3 billion 5-year US helicopter deal

(Adds Boeing clarification on value of options)

WASHINGTON, Aug 26 (Reuters) - Boeing Co (BA.N) said on Tuesday it won a contract valued at $4.3 billion for 191 CH-47F Chinook helicopters, plus options for 24 additional twin-rotor Chinooks in coming years.

The deal announced on Tuesday includes a five-year procurement agreement for 181 aircraft, valued at $3.6 billion, as well an initial $217 million option for 10 more helicopters, said Boeing spokesman Jack Satterfield.

He said the overall sum of $4.3 billion included the initial orders and all options.

Jack Dougherty, vice president of Boeing's H-47 programs, said the Army's decision to sign a five-year contract with Boeing would result in cost savings of over $449 million.

"This also builds security into our production schedule for the next five years, stabilizing the work force for Boeing and for our supplier partners in more than 45 states," Dougherty said in a statement released by Boeing.

Col. Newman Shufflebarger, Army project manager for cargo helicopters, said the deal would allow Boeing to enter long- term agreements for specialty metals, to include titanium, which would speed up work on the program by six months.

Boeing said it had already delivered 48 Chinook "F" models to the U.S. Army and the helicopter had completed several thousand flight hours since it received its combat-ready certification in 2007. The new helicopter is being used in Iraq.

The F-model of the Chinook has a new airframe, a cockpit equipped with a common avionics system built by Rockwell Collins Inc (COL.N) and a digital flight control system built by Britain's BAE Systems Plc (BAES.L). (Editing by Andre Grenon)