Air Canada firmed up an order for at least 45 Bombardier Inc. C Series jets, giving the much-delayed aircraft program a boost as the plane nears its commercial debut. The sale of CS300 narrow-body jetliners is valued at $3.8 billion based on list prices, Bombardier said Tuesday in a statement. Air Canada also has options for 30 more planes, which would boost the total deal value to $6.3 billion. Buyers typically negotiate discounts. The transaction makes Air Canada the the second-biggest customer of the C Series aircraft, after Delta Air Lines Inc., which agreed in April to buy at least 75 and potentially as many as 125 of the planes. Air Canada’s commitment follows the confirmation last week of a $1 billion investment by the Quebec government in a limited partnership that will build the C Series, which is more than two years late and $2 billion over budget. Deliveries to Canada’s largest airline will start in late 2019 and run until 2022, Montreal-based Bombardier said. Air Canada had signed a letter of intent to acquire the planes in February. The deal will help the carrier create a center for C Series maintenance work in Quebec, Air Canada Chief Executive Officer Calin Rovinescu said Tuesday. Deutsche Lufthansa AG’s Swiss International unit will take possession of its first C Series jet Wednesday at a ceremony in Mirabel, Quebec. Swiss is scheduled to begin commercial flights with the aircraft next month.