The CEO of Delta Air Lines doesn't want to be in business with Elon Musk. And Musk isn't happy about it.

"He will lose his job over this," Musk wrote on X earlier this week about Delta's Ed Bastian, responding to unconfirmed reports that the chief executive had criticized him during employee meetings.

The trigger for the billionaire's pique: Delta, the most profitable airline in the U.S., rejected Musk's Starlink in-flight Wi-Fi service, choosing Amazon's offering instead.

"Delta wanted to make it painful, difficult and expensive for their customers. Hard to see how that is a winning strategy," Musk posted on X in May.

The rants have set off a storm on social media. Musk fans and Delta loyalists piled in, generating strings of comments. Suddenly, all anyone could talk about was whether Delta's Wi-Fi is up to snuff. Sometimes, Musk joined the fray, echoing critical posts.

Delta's rivals are trying to make hay out of the moment. United extended an offer to match frequent-flier status for Starlink-curious Delta and American customers. American responded to one of Musk's posts touting its own status match.

Even notoriously no-frills carrier Frontier took the chance to remind fliers that it is getting Starlink next year.

Bastian and Delta have responded to the social-media invective by largely ignoring it. The airline wouldn't comment about Musk's digs, nor confirm that Bastian made any remarks circulating online attributed to him.

In the rare time he has engaged, Bastian played down the criticism, describing it as just the normal course of business.

"Of course, we expect Starlink will be warning people that we're going to go with an inferior product," Bastian told Bloomberg in May. "But I'm not too worried about partnering with Amazon."

This week, reports surfaced that Bastian had made disparaging remarks at company events about Musk's reputation and suggested Delta wouldn't want to work with him. Industry observer JonNYC, who posted the comments on X, said he couldn't verify them. Delta declined to comment.

Since reports of the remarks emerged, Musk's denunciations have taken aim at Bastian directly. "Any CEO who deliberately damages the company he runs due to some random personal gripe doesn't deserve to run their company!" Musk posted Thursday on X.

Behind Musk's jibes is a big battle over in-flight internet. Slow and expensive, Wi-Fi on planes has long been one of the most annoying parts of flying. Sometimes, passengers can't log on at all.

Now the airplane Wi-Fi wars are here. Free, fast in-flight internet has become a critical amenity for airlines to set themselves apart from the competition-and an opportunity for Amazon, Starlink and other providers that promises billions of dollars in the coming years.

Any in-flight Wi-Fi business would benefit from an association with Delta. It is accustomed to setting the standard for passenger experience. It blazed the trail for premium seating and luxury lounges that rivals now copy, for instance.

It also led the way in nixing Wi-Fi fees a few years ago at a time when among U.S. airlines, only JetBlue Airways offered it free. The airline says most of its planes now have "streaming quality" connectivity through providers Viasat and Hughes Network Systems.

Delta tested out Starlink's service years ago but held off. Instead it struck a deal earlier this year with Amazon's Leo satellite internet business to provide Wi-Fi on an initial 500 planes.

Bastian said at the time that Amazon's Leo would be just as fast as Starlink and more cost effective. Teaming up with Amazon, the CEO added, would allow Delta to build on its use of Amazon Web Services and to take advantage of Amazon's capabilities in retailing, gaming and video.

But Delta's Leo service won't start until 2028. For now, the Amazon unit is far behind Starlink in terms of getting into space the satellites that provide in-flight internet service.

Musk has criticized Delta for shortchanging fliers' internet access. "Best way to sandbox an AI is to put it on a Delta flight - it will have no chance of accessing the Internet!" Musk posted earlier this week, echoing a joke made by another user.

Meanwhile, Starlink installations are well under way at several rival airlines or are slated to start next year.

United Airlines, which has Starlink available on nearly half its daily flights and expects to finish outfitting its fleet by the end of next year, seized the opportunity this week to go after competitors' customers.

It extended an offer to match Delta and American fliers' status if they want to test out the zippy service. "Don't keep buffering," it wrote on a website where frequent fliers can apply for the match.

American, which also plans to start installing Starlink on hundreds of planes next year, posted a link to its own status match offer, "for anyone suddenly considering their airline loyalty."

Musk has a history of duking it out with executives, like with JPMorgan Chase's Jamie Dimon before the pair patched things up. His crusade against Delta and Bastian is tame compared with his last airline feud.

Earlier this year, Musk called for Ryanair CEO Michael O'Leary to be fired and threatened to buy the discount airline in order to oust him.

The brawl started when O'Leary said Starlink was too expensive and Ryanair had no plans to install it. Musk took to X to call O'Leary an "insufferable, special needs chimp." O'Leary shot back on Irish radio that Musk was "an idiot. Very wealthy, but he's still an idiot."

Ryanair, which has a habit of pouncing on free publicity, then launched what it dubbed its "Big 'Idiot' Seat Sale." O'Leary remains in charge of Ryanair.

United Airlines Chief Executive Scott Kirby, now one of Starlink's biggest boosters, also faced Musk's ire before becoming a customer. Musk engaged with posts criticizing United's diversity efforts and mocking Kirby.

After United became a Starlink customer, the company said it was aware of the posts but believed Starlink would benefit customers.