* Brazil's No. 3 airline exercises option for E-195 jets
* Order worth $478 mln at list prices, follows recent order
* Belarus airline to lease two E-175 jets
SAO PAULO, Feb 14 (Reuters) - Embraer, the world's third-largest commercial planemaker, booked an order for 10 regional planes from Brazilian airline Azul through the exercise of options, as the carrier grows its network of lower-traffic routes.
Delivery of the E-195 jets, worth a total of $478 million at list prices, will begin in 2015. The order comes just four months after Azul, Brazil's third-biggest airline, ordered 11 planes of the same model.
The deal brings Azul's total orders with Embraer to 62 aircraft, 33 of which are in operation, along with five E-Jets that the airline bought from other companies.
Embraer also said on Tuesday that Belarusian airline Belavia will lease two E-175 jets from Los Angeles-based Air Lease Corp.
The Azul order bolsters Embraer's forecast that stable demand this year in the regional commercial aviation market will allow it to replace deliveries with new orders of similar value, helping to maintain a backlog of firm orders that closed 2011 near $15.4 billion.
Embraer's chief rival for the segment, Canada's Bombardier Inc, said late last year it would cut regional jet production.
Shares of Embraer gained 1.2 percent in Sao Paulo as the benchmark Bovespa stock index shed 0.7 percent.