Shares of United Natural Foods (UNFI) - Get Report slumped Wednesday amid anxiety about the future of the wholesale food distributor's key contract with Whole Foods and disappointing quarterly earnings.

United Natural Food's stock price plunged 28% to $7.07 after an analyst from investment research firm CFRA raised concern about the status of the Whole Foods contract, the company's largest.

CFRA analyst Arun Sundaram warned that United Natural Food's stock price "could plummet" if the company's contract with Whole Foods, acquired by Amazon (AMZN) - Get Report in 2017, is not renewed by 2025.

The Providence, R.I., company also reported a miss on its quarterly earnings and a narrow beat on revenue.

United Natural Foods reported adjusted earnings of 12 cents a share, below the 23 cents a share forecast by analysts surveyed by Zacks Investment Research. It was also a decline from the 59 cents a share of the year-earlier period.

The wholesaler fared better when it came to revenue for the first quarter ended Nov. 2. UNFI generated $6.02 billion of sales, edging 3.5% ahead of the consensus of analysts surveyed by Zacks.

"We remain confident that UNFI is well-positioned today and for the future to deliver an industry-leading and sustainable supply chain platform for all customer channels," said Steven Spinner, chairman and CEO of United Natural Foods, in a statement.

UNFI's stock price has declined more than 50% since early 2019, when it hit a high of $15.19 on Feb. 25. That compares with double-digit gains by the S&P 500 this year.