Mesa Airlines (YV, Phoenix Sky Harbor) has announced it has expanded its partnership with United Airlines (UA, Chicago O'Hare) with the addition of twelve new E175 aircraft.

The Arizona-based capacity provider said in a statement issued last week the extra jets would increase the total number of the Embraer Regional Jets in service for United Express to sixty aircraft. Mesa also operates twenty CRJ700s for United Express.

“We are delighted, once again, to extend and expand our partnership with United Airlines with the addition of twelve new Embraer 175 aircraft,” Chairman and CEO Jonathan Ornstein said.

Deliveries of the twelve additional aircraft are scheduled to begin in May this year.