Germany-based air taxi developer Liliumhas won a major order from state-owned Saudi Arabian airline Saudia, a source familiar with the deal told Reuters on Wednesday.

The customer had signed a framework deal to buy 100 Lilium jets some 18 months ago and has invited reporters to an event which it said will give insight into Saudia's forthcoming deals at Lilium headquarters near Munich on July 18.

The source said the aim was to convert the deal into a concrete order for vertical take-off electric air taxis.

Lilium declined to comment specifically but sent an invitation to the same event, saying reporters would witness an important contract signing.

It would be one of the biggest orders for Lilium, which says it has 780 firm orders and letters of intent to date, including the plans with Saudia. The firm needs advance payments from customers to finalise the development of its flying taxi.

The first manned flight is scheduled for the end of the year.

(Reporting by Alexander Huebner, writing by Madeline Chambers, editing by Thomas Seythal)