AgustaWestland has secured two contracts worth £760 million from the Ministry of Defence.
The deal will boost economic confidence across the local area, according to South Somerset District Council leader Ric Pallister.
AgustaWestland in Yeovil, a Finmeccanica company, has been awarded contracts to convert 25 AW101 Merlin helicopters for maritime operations under the Merlin Life Sustainment Programme (MLSP) and to provide the Apache AH Mk1 Attack Helicopter fleet with comprehensive support and maintenance services for five years.
The contracts will help sustain around 175 highly skilled jobs at AgustaWesland and more than 500 jobs in the supply chain.
Mr Pallister said: "This order and the Norwegian deal announced before Christmas are hugely significant and vitally important for AugustaWestland as a company. However, it goes well beyond that for the people of South Somerset and the employment catchment area for the company and those businesses in the supply chain - be that accountants or local engineering companies.
"These orders provide security of employment and continuity for so many businesses across the district and that breeds confidence and success. Confidence to take out a first mortgage, confidence to move house, confidence to build that extension, confidence to expand a business or just the ability to take a much needed holiday. This confidence will help the local economy and everyone benefits. Unemployment continues to be at around half the national average and this news will undoubtedly help secure existing jobs and create new jobs and opportunities in the future."
A £1billion pound deal to build new helicopters for the Norwegian Government at AgustaWestland in Yeovil which will safeguard 3,000 jobs was also announced in late December.