Four relatively small Asian carriers already had a combined order book of more than USD 11 billion halfway into the six-day Singapore Airshow, with smaller planes as their preference.
Airline executives said many smaller cities in Asia remain underserved despite the explosive growth in budget air travel, and they will use the new planes to connect such destinations to metropolitan centres.
Asia's expanding middle class is driving demand, said Song Seng Wun, regional economist with Malaysian bank CIMB.
"It's really a function of regional economies experiencing spending power of the rising middle class which benefited from so many years of steady growth," Song told AFP.
In the latest deal, Indian carrier Air Costa today ordered 50 E-Jets E2 aircraft, which can seat 70-130 passengers, from Brazilian manufacturer Embraer worth USD 2.94 billion.
The deal with Air Costa, which began operations only four months ago, also includes purchase rights for 50 more of the aircraft, both companies announced at the show.
With the orders, Air Costa will become the first customer of the E-Jet E2 in the Indian market when it takes delivery of the first plane in 2018.
Thai budget carrier Nok Air also today firmed up orders for two Q400 86-seater planes from Canada's Bombardier worth USD 63 million.
Nok Air indicated it may buy six more depending on its needs.
The Singapore Airshow began Tuesday with an order by Vietnamese budget carrier VietJetAir for 63 Airbus A320 jets worth USD 6.4 billion.
The deal also covered rights to acquire or lease 38 more A320s, potentially boosting VietJetAir's current fleet of 11 A320s tenfold.
The Vietnamese airline, founded only in 2011, plies domestic routes as well as services to Bangkok, Seoul and Kunming in China with its current fleet of leased planes.
In another deal, US aircraft maker Boeing yesterday announced that Nok Air had committed to buy 15 B737s worth USD 1.45 billion.
Bangkok Airways, which brands itself as a "boutique carrier" that flies to selected tourist destinations, yesterday also signed up to buy six 72-600s from European plane-maker ATR in a deal worth USD 150 million.