Bombardier Aerospace is expected to announce an order for more of its new CSeries aircraft from Latvian airline Air Baltic as early as tomorrow.

According to industry sources, the aircraft are believed to be replacements for the carrier’s aging fleet of Boeing 737 Classics, and could number about 15 aircraft. Neither Bombardier nor Air Baltic were prepared to comment.

If confirmed, the commitment would be a major blow for Airbus, which competed for the order with its A319 and, as an option for later deliveries, the A319NEO.

Air Baltic also had been looking at the existing version of the A319 and weighing it against the 737-700 and 737-7 MAX.

Airbus Chief Operating Officer-Customers John Leahy has been talking down the sales prospects of the CSeries for some time, and at the Farnborough air show July 9 he reiterated that the A319NEO will be an aircraft for “all those people that don’t want to buy the CSeries.”

With Air Baltic trying to replace its narrowbodies as quickly as possible, timing and availability was also an important factor. The A319NEO will not be available before 2016 and the CSeries is scheduled to enter service by the end of 2013.

The Canadian manufacturer announced an order for 15 aircraft from an undisclosed customer on Sunday. Orders and commitments are now at 153 for the CS100 and CS300 combined.