Bombardier has inked tentative deals for a total of 12 CSeries aircraft from two unnamed customers at the Farnborough Airshow, taking it over 500 orders and commitments for the type.

The first deal, from an existing customer, covers seven firm CS300s and purchase rights on a further six. Bombardier valued the firm aircraft at $553 million at list prices.

Bombardier Commercial Aircraft president Mike Arcamone said this sale remains subject to board approval within the airline.

At the same briefing, Arcamone announced a letter of intent for five CSeries aircraft from an unnamed African operator, which already uses Bombardier products. This would mark Bombardier’s first African CSeries order, valued at approximately $365 million, if it is firmed.

“Our customer faces challenging operational environments and needs excellent range for hot-and-high performance as they expand into new and growing markets,” said Arcamone. He added that the CSeries’ fuel performance and comfort were key deciders for the unnamed carrier, particularly given the steep price of jet fuel in Africa.

To date, Bombardier’s firm order tally for the CSeries stands at 203 aircraft, but including commitments the program has now exceeded the 500 mark.

“We are very optimistic about the current status of our order book, which stands at 513 orders and commitments. We are well on our way to reach our target for 300 firm orders by entry into service, and have already achieved our 20 customer goal,” Bombardier Commercial Aircraft VP-sales, marketing and asset management Ray Jones said.