Airline apologizes to tennis star

United Airlines issued an apology to China's No 1 female tennis player on Thursday after members of its ground crew in Florida refused to allow her onto a flight with her racket bag.

Zhang Shuai, who is 34th in WTA rankings, fired off a series of angry posts on Twitter and Sina Weibo on Tuesday, accusing the carrier of "disgusting customer service" after a dispute at the check-in desk at Tampa International Airport.

She wrote that a female United employee took her tennis bag and tagged it with check-in tape without permission because she believed the baggage exceeded the maximum allowed size.