A clumsy comment from Delta's CEO, apparently linking Gulf-based air carriers with the 9/11 terrorist attacks, has sent the Atlanta-based airline into a PR tailspin.

The comment came amid a war of words between U.S.-based air carriers and their Arabian counterparts over what they say is unfair government help.

U.S. carriers claim that the "Gulf Three," Etihad, Qatar, and Emirates airlines are receiving billions of dollars in subsidies and have done so for many years, if not decades. They also allege that government handouts to Etihad have enabled the funding of new routes and new aircraft.

The Gulf airlines reject those claims. Qatar CEO Akbar Al Baker said he gets "equity" from the government, not subsidies.

In retort, the Gulf airlines point out that U.S.-based carriers themselves benefited from government help in the aftermath of 9/11.

This is where things began to go off the rails for Delta and its CEO Richard Anderson. On Monday he said that it was "a great irony" for Middle Eastern airlines to bring up the post-9/11 government assistance, especially since the terrorists who flew planes into New York's World Trade Center were from the Arabian Peninsula.

But it's not clear exactly what he meant. He said: "And it's a great irony to have the United Arab Emirates from the Arabian Peninsula talk about that, given the fact that our industry was really shocked by the terrorism of 9/11, which came from terrorists from the Arabian Peninsula, that caused us to go through a massive restructuring."

Delta (DAL) apologized Wednesday for Anderson's remarks, which he made on CNN's "Quest Means Business."

"He didn't mean to suggest the gulf carriers or their governments are linked to the 9/11 terrorists," the company said in a statement.

"We apologize if anyone was offended."