Alaska Airlines has agreed to buy Hawaiian Airlines in a US$1.9 billion deal that officials of the airlines say would create a stronger company to compete with the nation’s Big Four: American Airlines, Delta Air Lines, Southwest Airlines and United Airlines. It would also create a “clear leader” in the lucrative, $8 billion Hawaiian market, said Alaska CEO Ben Minicucci.

Officials called the deal a chance to combine two carriers with few overlapping routes, adding that the combined company would maintain both airlines’ brands, an unusual move in an industry where waves of acquisitions have led to four big brands dominating the US market.

“We combine two companies with shared values that have competed and survived longer than most through many industry cycles, enhancing our differentiated business model and creating a stronger competitor to network carriers,” Minicucci said.

The deal includes $900 million in Hawaiian debt, bringing the acquisition’s total value to $1.9 billion. The combined airline would be based in Seattle, with Alaska’s Minicucci at its head. The companies forecast the acquisition will add to profits within two years of the deal closing, which is forecast to happen between 12 and 18 months from now.

The combined airline would participate in the oneworld Alliance, which includes American Airlines, British Airways and Cathay Pacific.

Alaska and Hawaiian are both smaller than the nation’s dominant carriers. They said the deal would meld two complementary networks, increasing connectivity to 138 destinations for passengers travelling through the continental United States and across the Pacific, including nonstop service to 29 international destinations in the Americas, Asia, Australia and the South Pacific.

Hawaiian has a deep and long history within the islands, stretching back to its incorporation in 1929 under the name Inter-Island Airways.

The companies said they would keep Honolulu as a key hub and that the combination would triple the destinations that can be reached within one stop in North America for travellers from Hawaii.

The deal has been approved by the boards of both companies, but it still needs an OK from the shareholders of Hawaiian Holdings. It will also need the blessing of U.S. regulators, which have resisted more airline consolidation out of fear it could lead to higher fares.