American Express is officially selling its massive Costco business to Citi

What's Ahead in the Week: Can Costco Impress Investors With Earnings?
What's Ahead in the Week: Can Costco Impress Investors With Earnings?

American Express is selling its exclusive Costco portfolio to Citi.

Last February, American Express announced the end of the exclusive co-branding agreement on grounds that it couldn't find a deal that made better economic sense. The end of the deal was slated for this March.

In a statement Monday, American Express confirmed that it has sold the portfolio to Citi. The sale is expected to close in June, and all Costco customers with co-branded American Express cards will be transferred to Citi.

American Express could earn up to $1 billion from the sale, according to the statement.

See more of Costco stores:

This content is not available due to your privacy preferences.
Update your settings here to see it.

The loss of the exclusive deal with Costco was seen as a huge blow to American Express, which also recently lost an agreement with JetBlue, and faced an antitrust lawsuit from the Department of Justice.

And in a CNBC interview Monday, Warren Buffett, the company's largest shareholder, said the loss of Costco was a "big deal".

He spoke about American Express after a viewer question that wondered why Berkshire Hathaway is still invested in the company even after all its recent issues.

Buffett noted that it's a very strong brand with a great reputation that will continue to face lots of competition.

American Express shares were little changed in pre-market trading.

RELATED: 5 items to always buy in bulk

This content is not available due to your privacy preferences.
Update your settings here to see it.

NOW WATCH: How Apple Pay Could Destroy The Credit Card

See Also:

SEE ALSO: Warren Buffett will decide when it's time for changes at American Express