Apple Inc. spends $150 million on United Airlines tickets annually, making it the airline's largest global account.

And Cupertino, California-based Apple (Nasdaq: AAPL) spends $35 million annually on tickets to Shanghai, China, buying 50 business class seats every day, making Shanghai the No. 1 destination for Apple's travelers.

That's according to a sign photographed at San Francisco International Airport by Twitter user LAFlyer (the photo has been taken down but originally appeared here. Below is what the sign looked like on Twitter before it was taken down.)

United, a unit of United Continental Holdings (Nasdaq: UAL), didn't dispute the veracity of the sign, but told Business Insider in a statement that the "information was provided to United employees as part of a limited pilot project focused on San Francisco to highlight the importance of our corporate relationships and was not intended to be shared publicly." 

Read more at the Denver Business Journal: