Carl Icahn: I might consider getting back into Apple if not for this

Billionaire investor Carl Icahn , who earlier this year sold his position in Apple (AAPL), said Thursday he still thinks highly of the tech giant but remains concerned about its prospects in China.

"We made several billion dollars on [Apple]," Icahn told CNBC's " Squawk Box ," saying he thinks CEO Tim Cook is "doing a good job."

"I would get back in [to Apple] if I felt more secure about China," Icahn said. "I don't think anybody can tell you that China is not going to have a problem, even though it might be a very small one."

Icahn said he's worried about the high debt levels in China and how those might adversely impact the world's second-largest economy.

In Apple's latest quarter, sales declined 13 percent from the prior year, the first year-over-year revenue drop since 2003. Sales of iPhones slid to 51.2 million from 61.2 million the previous year.

Fiscal second quarter revenue and earnings missed estimates, while guidance from the tech company for the current quarter also fell shy of expectations.

Days after Apple released results in April, Icahn told CNBC he had sold his position in the tech giant . He previously owned a little less than 1 percent of the outstanding shares.

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