BERLIN (Reuters) - Lockheed Martin Corp's LMT.N Sikorsky has partnererd with more German firms in its bid to win a 4 billion euro ($5 billion) heavy-lift helicopter contract from Berlin, and will showcase the industrial team at next week's Berlin air show.

Lockheed Martin's logo is seen during Japan Aerospace 2016 air show in Tokyo, Japan, October 12, 2016. REUTERS/Kim Kyung-Hoon

“This shows how important this campaign is to us. We believe it’s a must-win,” Beth Parcella, who heads international sales for the Sikorsky program, told Reuters on Wednesday.

The U.S. weapons maker’s new Sikorsky CH-53K King Stallion helicopter will make its global debut at the Berlin air show with a “very compelling flight demonstration,” Parcella said.

The CH-53K , which the U.S. Marine Corps expects to declare combat-ready in 2019, will vie with Boeing Co's BA.N CH-47 Chinook to replace Germany's aging fleet of CH-53G aircraft.

Sikorsky said it is adding to deals already struck with Rheinmetall RHMG.DE, MTU Aero Engines MTXGn.DE and Hensoldt Sensors AG, by including ZF Luftfahrttechnik GmbH, Autoflug, Hydro Systems KG, the German unit of Rockwell Collins COL.N, Jenoptik Germany JENG.DE, Liebherr and Rohde & Schwarz.

The German defense ministry plans to issue a request for information in the second half of 2018 and award the winning bidder a contract in mid-2020, for deliveries to start in 2023.

Lockheed, in collaboration with Airbus-owned AIR.PA European missiles group MBDA, Britain's BAE Systems BAES.L and Italian group Leonardo LDOF.MI, is also negotiating with Germany's defense ministry on the TLVS missile defense system.

And the company is hoping to sell Germany dozens of F-35 fighter jets to replace older Tornado fighters.

Parcella said it was possible personnel changes in the German defense ministry and procurement agency could stall the program, but said it made sense to quickly replace the existing CH-53G fleet that has been flying for over 45 years.

“The legacy fleet will only become more expensive (to maintain) as time goes on,” she said.

Some German military officials favor the Boeing CH-47, which is flown by eight other NATO countries, but others say the larger CH-53K would allow growth in future missions.