Airbus Helicopters has signed a letter of intent for the sale of 100 H135 helicopters to China and the construction of an assembly plant there, a source familiar with the deal said Friday.

The 750-million euro ($800 million) deal for the versatile twin engine machines often deployed in emergency medical services came as German Chancellor Angela Merkel visits the Asian giant.

European manufacturer Airbus Helicopters has a 40 percent market share of a Chinese market which has identified 20-year demand of up to 5,000 copters.

The deal came a day after an accord between Airbus and state-owned China Aviation Supplies Holding Group for 100 A320 aircraft, worth $9.7 billion at list prices.

They also confirmed 30 options for twin-aisle A330s, among a 75-plane deal announced in June ahead of a visit by Li to Airbus headquarters in the French city of Toulouse.

Airbus -- which has an assembly facility in the northern Chinese port of Tianjin -- is engaged in a fierce struggle with the US' Boeing for dominance in the crucial Chinese market.

China is also developing its own fledgling aerospace industry even as it ramps up deals with foreign manufacturers.

dlm/fpo/cw/ser

AIRBUS GROUP