Illustration of food items placed on the belt of a cash register in a Leclerc supermarket in Valence, France, April 4, 2025.

Nicolas Guyonnet | Afp | Getty Images

LONDON — European stocks opened lower on Tuesday as tariff uncertainty causes global markets to waver.

The U.K.’s FTSE index is in the red by 0.4%, Germany’s DAX is down by 0.88%, Italy’s FTSE MIB is lower by 0.46% while France’s CAC 40 was trading flat. Meanwhile, the Stoxx Europe 600 index was lower by 0.6%

In corporate news, shares of private markets investor Partners Group have shot up to the top of the Stoxx 600 index after the company reported first-half profits of 578 million Swiss franc ($720 million) versus analysts consensus of 570 million Swiss franc, due to “due to higher performance fees.”

At the other end, Frankfurt-listed Fresenius Medical Care was at the bottom of the Stoxx 600 by 5.5% after analysts at UBS downgraded the stock to a “Sell” rating.

In Italy’s tumultuous banking consolidation story, state-backed Monte dei Paschi has bolstered its bid for domestic peer Mediobanca with a cash component of 0.90 euros ($1.05) per share, sweetening an original offer targeting 2.533 of its own stock for each Mediobanca share tendered.

This now represents a 11.4% premium against the close price of Mediobanca’s stock on Jan. 23. The Italian lender has been resisting Monte dei Paschi’s interest since the start of the year, rejecting the initial all-stock offer that runs to Sept. 8.

But last month’s failure to gain shareholder support for Mediobanca’s proposed purchase of Banca Generali – widely seen as a defensive play – has prompted some analysts to reassess the bank’s odds of avoiding a takeover down the line.

Regional bourses kicked off the new trading month higher on Monday, with the defense and health-care sectors receiving a boost from corporate news.

The mood has changed overnight, however, with Asia-Pacific markets trading mixed and U.S. stock futures little changed on Monday night, with investors weighing the trade landscape after a U.S. federal appeals court ruled that most of President Donald Trump’s global tariffs are illegal.

The U.S. Court of Appeals for the Federal Circuit determined in a 7-4 ruling that only Congress has the authority to apply sweeping levies. Trump called the decision “Highly Partisan” and has said that he will appeal the ruling to the U.S. Supreme Court.

Those developments could weigh on U.S. market sentiment in September, which is, historically, the worst month for equities, with the S&P 500 averaging a 4.2% drop over the last five years, and falling more than 2% on average over the last 10.

On Tuesday, regional investors will be keeping a close eye on euro zone inflation data released at 10 a.m. London time. Spanish unemployment data is also due.

— CNBC’s Sarah Min, Ruxandra Iordache contributed to this market report.