Southwest Airlines, ending years of speculation, officially announced late this afternoon that it will start selling tickets to Hawaii beginning next year and offer fares that are lower than those currently in the marketplace.

The Dallas-based carrier, known for its “bags fly free” and no-fee policies, said it wasn’t ready yet to identify the mainland-Hawaii routes it will fly, but said its large presence in California is an indication that some of the service will come from there. Company officials said they could not say yet when the service will begin.

Southwest executives also acknowledged that they are evaluating offering interisland travel — a move that would cut into Hawaiian Airlines’ stranglehold in the islands and potentially hurt smaller local carriers Island Air, Mokulele Airlines and Makani Kai Air. In addition, Southwest said it is considering nonstop flights to neighbor islands.

The airline said it is making the announcement now because it soon will begin a public application process to obtain the Federal Aviation Administration’s ETOPS (Extended Twin Operations) certification for operating aircraft between the mainland and Hawaii. That certification measures how far an aircraft can be safely away from land and over water if one engine gives out.

Southwest President Tom Nealon and Gov. David Ige made the joint announcement via satellite from Waikiki Beach behind the Royal Hawaiian to an estimated 10,000 Southwest employees at a company party at Universal Studios in Los Angeles.

In Los Angeles, Chairman and CEO Gary Kelly told the party-goers that “a day long-awaited by our customers, fans, and more than 55,000 of the world’s most-loved airline employees is finally within sight — a day that will showcase your hospitality, about as far Southwest as you can go in the U.S.”

Southwest Chief Revenue Officer Andrew Watterson, who worked for Hawaiian Airlines as vice president of planning and revenue management from 2011-2013, told the Honolulu Star-Advertiser that the company was purposely ambiguous about when flights would begin to and from Hawaii because that will depend on when ETOPS authorization is received.

“We wouldn’t be so bold as to say we’ll start flying in October or November or July of 2018 and not go through the FAA process,” Watterson said. “We know we’ll get through the FAA process in time to sell tickets next year, but until the FAA gives us better indications of the authorization timeline, we’re not going to speculate and put a date out there. This has been a long time coming so there’s no particular reason for us to rush it. For us, it’s more important to do it properly than doing it a certain date.”

Watterson said the airline, which is the first operator for the Boeing 737 MAX 8 aircraft, will use those 175-seat planes for Hawaii service. Southwest received nine MAX 8s on Oct. 1 and will have 14 by the end of this year.

Airline experts said despite the increased competition between Hawaii and the mainland that fares are not expected to change much because it costs more per mile to operate Southwest’s aircraft than the larger planes operated by Hawaiian Airlines and other carriers.

But Watterson refuted the notion that Southwest won’t be able to offer lower fares.

“Our seat-mile costs are below (other airlines serving Hawaii) and we will offer lower fares than currently are in the marketplace. You can count on that,” he said. “One hundred and seventy-five seats in a 737-800 is a different scale of economy and we can keep costs low by higher efficiencies.”