I'm selling 6 times more than buying: Wilbur Ross

Ross: Courage to buy BankUnited

With the stock market recently at all-time highs, before Thursday's sharp selloff in futures and weakness earlier this week, it's more attractive to sell than buy, private-equity billionaire Wilbur Ross said.

"On balance we've been a seller. We've sold six times as much as we've bought so far this year … everywhere," the investor in distressed assets told "Squawk Box" on Thursday.

Ross said stock valuations in the U.S. are high, and "with markets [near] at all-time highs, it shouldn't be surprising that there are more things that are attractive to sell than to buy."

U.S. stock futures were sharply lower Thursday, signaling a triple-digit loss at the open for the Dow Jones Industrial Average, following Wednesday's rebound on the release of dovish minutes from the Federal Reserve's June meeting. The selling early Thursday accelerated following a sharp slide in European stocks on weak economic data from Italy and concern about Portugal's largest listed bank.

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With a track record of successfully investing in troubled European banks, Ross told CNBC he considered Banco Espirito Santo, but took a pass.

"We couldn't get our arms around it," he said. "We didn't feel we really understood the balance sheet."

"We've kind of run out of big countries to invest in so we're now going to the smaller ones," said Ross, chairman of WL Ross & Co. He said he's also looking at Spain, Greece and Cyprus in addition to Portugal.

About a month ago, Ross and other international investors invested $1.8 billion in Eurobank—becoming the bailed-out Greek bank's biggest shareholders in another sign of growing market confidence in Greece.

"It's off to a really, really good start," he said.

In one of his first major European investments after the 2008 financial crisis, Ross put money into the Bank of Ireland in 2011, which helped keep it out of state hands at the height of the euro zone debt fallout.

—By CNBC's Matthew J. Belvedere