Republic Airways and Mesa Air Group Inc. are combining in an all-stock deal that will create a regional airline with access to more planes to service routes.

Specific financial terms of the deal weren't disclosed in a statement Monday.

Republic, started in 1974, has a fleet of more than 240 Embraer 170/175 aircraft and carried about 17.5 million passengers on more than 300,000 flights last year. It mostly serves Northeast and Mid-Atlantic hubs and operates exclusively under long-term capacity purchase agreements with American Airlines, Delta Air Lines and United Airlines.

Mesa Air Group, founded in 1982, is the holding company of Mesa Airlines, a regional air carrier that offers service to 89 cities in 40 states, the District of Columbia, the Bahamas, Canada, Cuba, and Mexico. It runs a fleet of 60 Embraer 175 aircraft with more than 250 daily scheduled departures and has approximately 1,700 employees.

Mesa operates all of its flights as United Express under the terms of a capacity purchase agreement with United Airlines.

The combined airline will have a single fleet of approximately 310 Embraer 170/175 aircraft, with more than 1,250 daily departures. It will continue to serve American Airlines, Delta and United Airlines and anticipates keeping all flight crews, technicians, and other operational staff.

“Republic and Mesa share a common mission to connect communities across America, and we believe that we can better achieve that mission together," Republic President and CEO Bryan Bedford said in a statement on Monday. "With this combination, we are establishing a single, well-capitalized, public company that will benefit from the deep expertise of Republic and Mesa associates, creating value for all stakeholders well into the future.”

The combined company will be called Republic Airways Holdings Inc. and will be listed on the Nasdaq under the new ticker symbol “RJET.” Its board will include six existing directors from Republic's board and one independent director from the Mesa's board.

Once the transaction closes, Republic shareholders will own 88% of the combined company’s stock. Mesa shareholders will own at least 6% and up to 12% of the combined company, dependent on achieving certain pre-closing criteria. All outstanding Mesa debt obligations will be extinguished as a result of the transaction.

Both companies' boards have approved the deal, which is targeted to close in either the late third or early fourth quarter. It still needs approval from the shareholders of both companies.

Shares of Mesa Air Group, based in Phoenix, Arizona, surged more than 67% to $1.20 before the market open.