European markets ended the week on a high note after U.S. data showed that showed the economy may be gaining momentum. According to the data, retail sales jumped in 1.3% in April. That was the biggest jump since March 2015.

Data from the Eurozone was not as good, with GDP growth falling short of expectations. Figures released by the European Union's data arm Eurostat showed that GDP had expanded 0.5% from the previous quarter and 1.5% year-on-year.

According to the statistics, Greece was the worst performing country in the Eurozone, with its economy contracting 0.4%. Greece's ASE Index fell 1.59%.

In London, the FTSE 100 closed at 6,138.50, up 0.56%. The index was weighed down after yet another warning about the potential impact of a U.K. retreat from the European Union.

The International Monetary Fund warned today that if the U.K. were to leave the European Union it would cause a period of heightened uncertainty and financial market volatility. The IMF also warned that London's status as a financial center could suffer.

The index slid after the announcement but later recovered.

The biggest gainer on the index was Tesco (TSCDY) , closing 3.9% up. The supermarket chain today released its annual report that showed the CEO Dave Lewis received a 12% pay increase and a bonus of £3 million ($4.3 million). Shareholders don't usually rejoice such increases, but he was responsible for turning a profit at the scandal-ridden grocery store.

The company posted a pretax profit of £162 million in 2015, compared with a £6.2 billion loss in 2014.

London-listed Coca-Cola Hellenic suffered losses, closing 3.5% down in London after it announced that quarterly net sales fell 2.7%. The company saw weak sales in Russia.

The Dax ended the week at 9,952.90, up 0.92% on Thursday's close. And in Paris, the Cac 40 was up 0.62%, closing at 4,319.99.

In Frankfort, BMW (BAMXY) was one of the worst performers on the Dax, closing 2.6% down, as was adidas (ADDYY) , which closed 3.1% down.

In Milan, Salvatore Ferragamo (SFRGY) closed 8.1% up despite declining quarter sales in Europe, Asia Pacific and overall as the luxury goods company made progress on cost control. Both operating and net profit rose, with the bottom-line figure up 6.3% at €34 million ($38.6 million).