Atlantic Coast Airlines Holdings Inc., parent of new low-cost carrier Independence Air, said yesterday it lost $27.1 million (60 cents a share) in the second quarter, largely because of start-up costs for Independence, which began service June 16.

The Dulles company reported earnings of $45.7 million ($1.01) in the same period last year. It said, for instance, that it spent $17.7 million on sales and marketing in the second quarter, compared with $5.8 million a year ago.

The 15-year-old company has been making a transition this summer to a new role as a stand-alone airline after operating regional jets for UAL Corp.'s United Airlines and Delta Air Lines Inc. Independence Air is serving 22 markets. By Sept. 1, the airline said it will have operations in 35 markets with 600 daily flights in and out of its Dulles hub.

The company reported revenue in the second quarter was down to $190.5 million, compared with $227.1 million a year ago, partly because United began phasing out its operations in early June.

Atlantic Coast Chairman Kerry B. Skeen said the company will end its relationships with United on Tuesday and with Delta in the fall. On Wednesday, Atlantic Coast plans to roll out a new name -- Flyi Inc. And the company's symbol on the Nasdaq stock market will change that day from ACAI to FLYI.

"What we have accomplished to date is just quite remarkable," Skeen said. "We've opened 23 stations without a hitch, really." The second-quarter losses were slightly higher than the company and analysts had expected.

Robert N. Ashcroft, an analyst for UBS Investment Research, yesterday cautioned investors to expect "high volatility" from the stock in the coming months. He added in a research note that the company "is in for punishment for the next year or so. FLYI execution, competition and distribution (of tickets) are the big issues . . . But it's not unknown for organizations to rise to the occasion."

Skeen said he had not anticipated a dispute over revenue with United Airlines, which is operating under protection from its creditors. He said United withheld $1.1 million from payments due in June as part of a separation agreement, and Atlantic has filed a motion in bankruptcy court to collect the money.

Atlantic Coast also put $1 million in reserve for a Federal Aviation Administration fine and potential liability related to a labor dispute.

The company's shares were down 10 cents, or 2.7 percent, to close yesterday at $3.61.

Despite quarterly loss, Chairman Kerry B. Skeen is pleased with the launch of Independence Air.