(Bloomberg) -- The supply chain turmoil that’s led to global product shortages will have a muted impact on advertising, according to the head of the world’s largest ad agency.

“We haven’t seen any impact yet of supply chain shortages,” WPP Plc Chief Executive Officer Mark Read said an interview Thursday, after the firm reported third-quarter sales that surged past expectations. 

Read’s reassurance comes just days after Snapchat parent Snap Inc. warned that supply chain bottlenecks are prompting some companies to hold back online ad spending for the upcoming holiday season. That rattled investors and erased about $142 billion of market value from the company and its peers.

Read more: Snap Shortfall Shows Supply-Chain Woes Hitting Social Media 

“As we sit here today, I’d say we don’t expect supply chain issues to have a material impact on spend in the fourth quarter,” Read added. “We do look at it carefully but in our guidance for the year we do expect a strong second half overall.”

WPP shares were up as much as 4.7% to 1,011.5 pence on Thursday, the biggest gain since January.

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