The two plane makers have until year-end to submit proposals, said Cebu Pacific, which aims to more than double its fleet by 2035 to take advantage of a long-term travel boom across Southeast Asia following the pandemic.
"To service the Filipino market over the next 20 years, Philippine carriers will need to quadruple in size," Cebu Pacific CEO Michael Szucs said in a statement.
The Philippines' prospects are driven by high economic growth, a young population and proximity to regional hubs, Szucs said.
The $12 billion figure was based on list prices, said the airline's president, Alexander Lao. Airlines typically get discounts on big orders worth at least half the headline price, analysts say.
The Inquirer newspaper on Tuesday reported that Cebu Pacific will seek out the best offer in a winner-takes-all deal, quoting CEO Szucs.
Cebu Pacific is the Philippines' largest budget carrier, operating a fleet of 73 Airbus and ATR aircraft, which will increase to 91 by end-2024.
Cebu Pacific, which flies to 35 local destinations and 25 international locations, booked a net profit of 3.75 billion pesos ($66.1 million) in the first half, reversing a 9.5 billion net loss a year earlier.