Updates prices, adds detail and investor comment

By Samuel Indyk and Danilo Masoni

LONDON/MILAN, Feb 3 (Reuters) - A selloff in European and North American software, data analytics and advertising stocks deepened on Tuesday after new artificial intelligence models raised concerns over the potential impact on sectors once seen as AI beneficiaries.

One catalyst was the launch of Anthropic's legal plug-in for its Claude generative AI chatbot, according to traders and analysts.

The move sent Britain's RELX REL.L and the Netherlands’ Wolters Kluwer WLSNc.AS, both providers of legal analytics services, down as much as 17% and 13% respectively. Toronto‑based Thomson Reuters TRI.TO, which owns the Westlaw legal database, fell over 14%.

"The software companies were assumed to be winners from AI," said Lars Skovgaard, senior investment strategist at Danske Bank. "But all of a sudden, you start to worry about whether you can earn the money back (from your AI investments), and/or will you be outsmarted by updates coming in."

RELX shares have now almost halved from their peak last February and on Tuesday were set for their biggest drop since 1988. Its dramatic reversal highlights the pressure AI is exerting on Europe’s software sector.

Germany’s SAP SAPG.DE, which less than a year ago was Europe’s most valuable company, slumped over 16% last week after its cloud revenue forecast missed expectations, wiping about $40 billion off its market value in one day. Its shares were down 4.9% on Tuesday and more than 41% below 2025’s high.

"Artificial intelligence is increasingly able to perform exactly the sort of programming and knowledge‑based services that underpin these business models, so parts of the sector have been under pressure for some time," said Giuseppe Sersale, fund manager at Anthilia.

U.S. software and cloud computing stocks also fell. Microsoft MSFT.O and Oracle ORCL.N were down 2% and 3% respectively. Salesforce CRM.N, ServiceNow NOW.N and Photoshop maker Adobe ADBE.O all fell over 5% in early trading.

Other professional services firms were also sharply lower. In London, Experian EXPN.L, Sage Group SGE.L, London Stock Exchange Group LSEG.L and Pearson PSON.L fell between 4% and 10%. Traders and analysts said fear often outweighed company fundamentals.

ADVERTISING COMPANIES HIT

Advertising companies were also under pressure. France's Publicis PUBP.PA shares dived over 9% after the company's results, while U.S.-based Omnicom OMC.N slumped nearly 6%.

Publicis, the world's largest advertising group by market capitalisation, said it had earmarked approximately 900 million euros ($1.06 billion) for acquisitions in 2026, focusing on AI-powered technologies and data assets.

According to a Barclays survey of buy-side investors published on Monday, advertising agencies are seen as the most exposed part of European media to artificial intelligence, with WPP WPP.L, Omnicom OMC.N and Publicis ranked the top "AI losers".

Analysts at the bank said companies could most effectively shake off an "AI loser" label by launching and clearly promoting revenue‑generating AI products.

Other firms that rely heavily on advertising were also hammered, with Pinterest PINS.N slipping 4% and Snap SNAP.N falling more than 5%. Ad-dependent Big Tech companies Meta META.O and Alphabet's GOOGL.O Google, however, were down only marginally.

($1 = 0.8481 euros)