BERLIN, July 1 (Xinhua) -- Germany's family enterprises barely increased their sales revenues in the past year, German media Der Spiegel reported on Tuesday based on a study of the Stuttgart Institute for Family (IFF).

The 50 largest German companies earned an added revenue of 938 billion euros (1,285 billion U.S. dollars) in 2013, while it was 930 billion euros one year earlier.

One reason for deceleration in growth is the strong euro, which get partly lost through the additional revenue in other currency.

Another reason is the fear of family enterprises of acquisitions, said the report.

"Many family businesses are still cautious. Such as difficulties of the Merckle family or the most risky acquisition of Continental by Schaeffler are not forgotten," said Mark Binz, Chairman of the IFF, to Der Spiegel.

Despite weak revenue growth, the number of employees in the top 50 family enterprises rose to 3.7 million people in 2013, an increase of 2.7 percent compared to the previous year.

Family enterprises are an important economic factor in Germany. According to the Federation of German Industries, 90 percent of all the four million German companies are managed by families or bearers.

Meanwhile, according to the Institute for Small Business Research, family enterprises account for more than half of all jobs in Germany. (1 euro = 1.37 U.S. dollars)