European markets mixed, Erste Group Bank rises 7% after acquiring stake in Santander's Polish unit

European bourses had a mixed start to the week on Monday, with U.K. markets closed for a bank holiday, as investors looked ahead to the latest economic data and corporate earnings reports due this week.

Germany's DAX was last 0.39% higher, while Italy's FTSE MIB was trading around the flatline and the French CAC 40 fell 0.55%.

Santander on Monday announced that Austria's Erste Group Bank had acquired an around 49% stake in Poland-based Santander Bank Polska and 50% of Polish asset manager Santander TFI. Shares in Erste Group were last around 6.5% higher.

Amsterdam-traded shares in Shell meanwhile were last around 1.7% lower after Bloomberg reported the energy giant was evaluating a potential acquisition of its rival BP.

"As we have said many times before we are sharply focused on capturing the value in Shell through continuing to focus on performance, discipline and simplification," a spokesperson for Shell said in response to CNBC's request for comment.

Data released Monday showed that Swiss inflation fell to 0% in April compared to the same month a year earlier, coming in lower than expected. Turkish inflation meanwhile rose 3% in the month of April, taking the annual rate to 37.86%.

While it will be a quiet start to the week on the earnings front, several major companies are due to report in the coming days including Novo Nordisk, BMW, Maersk and Commerzbank.

Central Banks across Europe will also be in focus this week, with Sweden's Riskbank, Norway's Norges Bank and the Bank of England among those announcing their latest interest rate decisions.

Many Asian markets were also closed for a holiday Monday. Australian stocks fell after Prime Minister Anthony Albanese claimed victory as the country's first prime minister to secure a second consecutive term in 21 years.

U.S. stock futures were last lower after a winning week that saw the S&P 500 record its longest positive streak in two decades. Trade tensions and prospective deals with the U.S.' key partners continued to be top of mind for investors, as was the upcoming interest rate decision from the Federal Reserve. The central bank is widely expected to keep rates steady.