Southwest Airlines says shutdown cost it as much as $15 million this month

• Southwest Airlines says the shutdown cost it $10 million to $15 million this month.
• Southwest beat earnings and revenue expectations, sending shares sharply higher.
• The shutdown's revenue hit has been small, but airlines are worried about impacts as it drags on into a second month.

A Southwest Airlines jet leaves Midway Airport in Chicago, Illinois.

Scott Olson | Getty Images

Southwest Airlines said Thursday it has lost $10 million to $15 million this month due the partial government shutdown.

The estimate comes a week after rival Delta Air Lines said it likely lost about $25 million in January with fewer government employees and contractors working as the shutdown enters its second month.

The amounts are small compared with carriers' overall revenue. Southwest posted $5.7 billion in revenue in the last three months of the year, slightly above analysts' expectations. Shares of the low-cost airline were up close to 4 in morning trading after the company beat analyst's earnings expectations.

The industry has been feeling the impact from the shutdown since airlines need government approvals to start flying new jets and new routes. Southwest has had to delay its plans to start service from California to Hawaii because federal safety approvals are on hold.

"Our remaining work is currently suspended until the government reopens and the FAA is allowed to resume normal certification activities," Southwest said in its earnings release Thursday. "We are anxious for the government to resolve this shutdown so we can bring low fares and a boost to Hawaii's travel and tourism industry."

Southwest said travel demand remains strong.