Budget carrier IndiGo announced on Tuesday it has placed a firm order for 300 A320neo family aircraft, comprising A320neos, A321neos and A321XLRs.
The airline, however, did not disclose the value of order.
With this, IndiGos total number of A320neo family aircraft order now stands at 730, the airline said in a statement.
"This order is an important milestone. India is expected to continue with its strong aviation growth and we are well on our way to serve more customers and deliver on our promise of providing low fares, among others," said Ronojoy Dutta, chief executive officer, IndiGo.
This marks one of Airbus largest aircraft orders ever with a single airline operator, the airline said.
IndiGo had earlier in three tranches placed orders for 530 Airbus planes between 2005 and 2015.
"We are delighted that IndiGo, one of our early launch customers for the A320neo, continues to build its future with Airbus, making IndiGo the worlds biggest customer for the A320neo family, said Guillaume Faury, chief executive officer, Airbus.