PayPal is exploring an acquisition that would value Pinterest at around $39 billion, Bloomberg first reported, citing people with knowledge of the matter. Reuters and the Wall Street Journal also reported PayPal's interest, citing sources. The companies did not immediately respond to a request for comment from CNN Business.

Shares of Pinterest (PINS) spiked nearly 12% late Wednesday morning, before giving up some of those gains.

Pinterest, often considered a more feel-good corner of the internet, has nonetheless faced some controversy. The company announced earlier this year that it would ban ads related to weight loss after problems with content on its platform that promoted potentially harmful eating and lifestyle habits.

Pinterest also paid $22.5 million last year to settle a gender discrimination lawsuit brought by its former chief operating officer Francoise Brougher. (Pinterest did not admit to liability as part of the settlement.)

PayPal (PYPL) has a history of big-ticket acquisitions, buying Japanese buy-now-pay-later service Paidy for $2.7 billion last month. The company's previous purchases include mobile payments platform Venmo and shopping reward site Honey.

In recent years, Pinterest has introduced more shopping features and also partnered with Shopify to make it easier for sellers to use Pinterest to reach potential customers.