Separate data releases from France and Germany failed to meet expectations on Friday.
Preliminary data from Germany's federal statistics office showed the economy grew 0.4 percent in the second quarter, from the previous three months, aided by a weak euro and positive export growth. It failed to match up to expectations for 0.5 percent growth by analysts polled by Reuters.
Meanwhile, French GDP data for the same time period showed the economy slowed to a standstill, missing expectations of 0.2 percent growth from analysts.
Interestingly, the only country that shrunk the second quarter was Finland. Its economy declined by 0.4 percent between April and June, continuing a recession that has seen the Nordic country shrink annually since 2012.
Jennifer McKeown, senior European economist at Capital Economics, said the outlook for the euro zone was mixed.
"Looking ahead, business surveys suggest that the euro-zone economy will continue to expand, led by strong growth in Spain and a solid German economy. But they offer little hope that the recovery will gain pace. Indeed, we think it is more likely that growth in the region as a whole will slow further in the second half of the year," she warned in a research note on Friday.
The mixed outlook underlined the need for the European Central Bank to maintain "and perhaps extend" its quantitative easing program, she added.
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