Ukraine International Airlines is taking over a pair of Boeing 737-800s from the fleet of troubled AeroSvit.
The acquisition will expand UIA's fleet from 19 to 21 737s, including six -800s.
UIA says the aircraft were formerly operated by AeroSvit but have already undergone re-registration, to become UR-PSE and UR-PSF.
AeroSvit took its first 737-800 only in March last year, part of a batch of seven of the type ordered in 2007.
The airline had also intended to acquire four 737-900ERs.
UIA has already repainted the first 737-800 from AeroSvit with a hybrid livery, featuring AeroSvit's yellow and blue fuselage scheme but with UIA's titles and fin logo.
It says the aircraft are subject to a 12-year lease with a European lessor.
Another pair of 737-800s are due to join the UIA fleet in April-May 2013, the carrier says, taking its fleet to eight.
In the wake of the crisis enveloping AeroSvit, Ukraine's prime minister says the government intends to develop a "competitive strategy" for air transportation.
This will "minimise the risk of recurrence" of problems which have engulfed the airline, says Mykola Azarov.