The Canadian manufacturer in October agreed to sell a majority stake in the C Series program, but the deal is awaiting regulatory approval. In the meantime, Bombardier and Airbus cannot coordinate on sales campaigns for the 110-130 seat jets.

Bombardier Commercial Aircraft sales head Colin Bole said the long-term sales prospects for the C Series had strengthened as a result of the Airbus deal, but it could be causing some temporary delays in order decisions.

"I won't deny it does create probably a bit of a pause in the meantime," he told Reuters at the Singapore Airshow. "Most airlines at least are trying to understand what this means in the long run."

Bombardier agreed the joint venture with Airbus when it was fighting off a move by rival Boeing Co to have the U.S. levy heavy duties against the C Series jet.

The Canadian firm won an unexpected victory against Boeing in the trade dispute last month, but it is pushing ahead with plans to assemble the jet for U.S. customers in Alabama regardless, Bole said.

As Airbus and Bombardier work to complete the C Series deal this year, the Canadian firm's Brazilian rival Embraer SA is discussing a tie-up with Boeing.

U.S. carrier JetBlue Airways Corp last month said it had extended a review on the future of its Embraer E-190 jet fleet due to the evolving commercial landscape.

"The market for smaller and mid-size aircraft is going through tremendous change with the recent Airbus-Bombardier deal and Boeing-Embraer talks," it said in an email to its staff reviewed by Reuters.

With the Airbus deal yet to be completed, Bombardier is hoping for a strong year of sales for its Q400 turboprops after having received 41 orders last year.

The Q400 turboprop has a lower market share than Franco-Italian rival ATR.

"Last year was a very successful year for the Q400," Bole said. "I expect a similar year or even better year this year. We are building that market share."

(Reporting by Jamie Freed and Tim Hepher in Singapore; additional reporting by Allison Lampert in Montreal Editing by Muralikumar Anantharaman/Keith Weir)

By Jamie Freed and Tim Hepher