SAS AB may have to cut its profit outlook as airline pilots extended a strike in protest over pay and work hours.

The walkout, which has already disrupted the plans of hundreds of thousands of passengers, will continue into Wednesday, with SAS saying it’s been forced to cancel another 504 departures across Scandinavia. Talks between the two sides appear to have reached a stalemate.

Shares in SAS traded about 3.8 percent lower in Stockholm by noon on Tuesday. Savings adviser Nordnet estimated on Monday that analysts tracking SAS were probably going to have to cut their average expectations for earnings per share by about 30 percent. At DNB, analysts cut their rating on the stock to hold from buy because of the strike.

The standoff underscores the challenges facing airlines as they try to cut costs amid competition from discount rivals against a backdrop of overcapacity across Europe. The Nordic region has become a particularly tough battleground, with Iceland’s Wow Air and leisure carrier Primera Air going out of business and Norwegian Air Shuttle ASA scrapping routes and delaying jet orders to help ease its debt burden.

Since starting late last week, the strike already looks set to cause well over 3,000 cancellations, affecting about 330,000 passengers.

Rickard Gustafson, chief executive officer of SAS, said he is “deeply concerned that the pilot strike hasn’t been resolved and that it is continuing to affect our customers,” in a statement on Tuesday.

“The demands made by the pilots’ unions entail significant cost increases for SAS that would threaten the company’s long-term competitiveness and consequently, the jobs of all SAS’s employees,” he said. For now, the talks “remain in a deadlock,” he said.

While the Stockholm-based airline company says it’s still too early to provide an estimate of the cost, analysts have started to do the math. Per Hansen, an investment economist at Nordnet in Copenhagen, said on Monday that five days of strikes through Tuesday alone would cost SAS about 500 million kronor ($53 million), with no guarantee that the pilots will return to work any time soon.

“On top of costs toward compensation, the loss of income from tickets and wage costs for all personnel groups aside from the pilots, SAS is also missing out massively on new ticket sales over the coming one to two weeks,” Hansen said. “No one wants to order a ticket that might end up not being worth anything and where there’s a risk of having to pay more to re-book.”

Meanwhile, other airlines are making the most of SAS’s predicament. Norwegian Air Shuttle has deployed extra aircraft to lure passengers stranded by the SAS pilot strike.