Wichita ? Bombardier Aerospace will build its new midsize Learjet 85 in Wichita, investing $600 million to expand its facilities and adding hundreds jobs in exchange for millions in bond financing from the state.

The final assembly work for the plane will mean 600 jobs, with 300 of them new positions, the company said Friday. It also includes a guarantee that Bombardier will keep its existing operations in the state.

Steve Ridolfi, Bombardier’s business aircraft president, told employees and government officials that the past 18 months have been extremely difficult for the aviation industry.

“The economic conditions are still challenging and so we must continue to manage our business prudently,” Ridolfi said. “However, the fundamentals of business aviation remain strong. The future of the industry looks bright. To that end, we are starting to see the light at the end of the tunnel in the form of increased flight hours, diminished inventory and, dare I say it, new sales.”

Bombardier’s changes at the Learjet site will include a new paint facility, customer delivery center, production flight test facility and expanded production hangars for final assembly of the plane.

Delivery of the first Learjet 85 is expected in 2013. The eight-passenger Learjet 85 will be Bombardier’s largest, fastest, longest-range Learjet model to date. Bombardier has more than 60 orders for the aircraft, enough to keep workers busy for two years of production already, Ridolfi said.

About 300 employees are working on project now, and the additional jobs will be progressively added from now until 2013, he said.