A lower-fare battle is beginning.
JetBlue Airways plans to announce today that on Sept. 9 it will begin daily flights from Logan International Airport to Baltimore-Washington International Thurgood Marshall Airport.
Southwest Airlines earlier this month said it would launch service from Boston to Chicago Midway Airport and to Baltimore on Aug. 16.
JetBlue, which already has six daily nonstop flights between Boston and Washington Dulles International Airport, will offer four daily flights to Baltimore. Introductory prices will start at $39 for one-way fares purchased before May 4. Southwest said it will offer introductory fares as low as $89 one-way for Chicago and $49 one-way for Baltimore.
"JetBlue's in the business of giving customers more than the other guys, so today we are pleased to announce even more flights to the Washington area," said Scott Laurence, JetBlue vice president of network planning.
The new flights are good news for Boston travelers. When Southwest, which carries more passengers than any other US airline, enters a market, it tends to ratchet up pressure on rivals, driving down prices.
This may be particularly true at Logan, as it is not dominated by any single airline and already offers service from a number of other lower-fare carriers, including Virgin America, AirTran Airways, and Spirit Airlines.
"This move by JetBlue suggests that things will be much sweeter for the people in Boston," said Rick Seaney, chief executive of Farecompare.com, a website that tracks airline fares and trends.
Daniel M. Kasper, managing director of Cambridge aviation consulting firm LECG LLC, said yesterday that JetBlue's move is atypical of the so-called Southwest effect, in which "Southwest moves into a market and the legacy carriers cut their prices. This battle of discount carrier vs. discount carrier is a bit more unusual," he said.
But the move is in line with JetBlue's Boston strategy. The airline said in October that Boston was one of the three most important cities in its growth strategy, which focuses on luring more business travelers and charter flights for companies and teams. It also said it would increase its Logan operations this year.
"Baltimore will be our 32nd city from Boston," said Sebastian White, a company spokesman, in a statement. "And in a nod to the growing importance of Boston, it will be a city served only from Boston."
To be sure, the decision to start service to Baltimore is strategic, coming little more than a week after Southwest detailed its plans for service from Logan, with five daily nonstop flights each to Chicago Midway and Baltimore, two of the most popular of the carrier's focus cities.
JetBlue already offered direct daily service to O'Hare International Airport in Chicago, but not to Baltimore.