Advertising mogul Martin Sorrell told CNBC on Friday his company plans to double its investment in Snap this year.

“But it’s at very low levels. It’s $200 million versus $6 billion or $2 billion for Facebook. So, you’re talking about a flea on the elephant’s backside,” the CEO of WPP said in a wide-ranging interview on “Squawk Box.”

“I think (Snap is) potentially more competitive as the third force,” Sorrell added, saying he still likes Snap over Facebook.

Last year, WPP spent about $100 million on Snap, and Sorrell said that could grow to $200 million this year. But WPP’s spending on Facebook was about $1.7 billion last year and will be “well over” $2 billion this year, Sorrell said.

Snap shares were higher in premarket trading Friday but the stock hit a new all-time low Thursday amid a number of market jitters, including Facebook eating Snap’s lunch. The stock is down 42.76 percent over the past three months, according to FactSet.

Snap’s “lockup” period has also expired, allowing company insiders and early investors to unleash their shares into the market. The company is scheduled to release its quarterly earnings report later this month.

Sorrell on Friday also spoke about social media companies fighting the rise extremist content. He said Facebook and Google are making significant steps but must be “as vigilant as you possibly can.”

Disclosure: CNBC parent NBCUniversal is an investor in Snap.

— CNBC’s Anita Balakrishnan contributed to this report.