Contracts signed today "cover all development work on Ariane 6 and its launch base for a maiden flight in 2020," ESA said in a statement.
ASL noted that Ariane 6 is slated to reach "full operational capacity" in 2023 under the deal.
ESA also stated that European Launch Vehicle would develop the Vega C launch system for its 2018 debut, at a cost of 395 million euros.
The contract for the Ariane 6 launch base totals 600 million euros, ESA said, adding that the deals were signed by ASL, ELV and the French space agency CNES.