The European Union's statistics agency revised up Germany's budget surplus for 2018, data released on Monday showed, following a trend that could signal Berlin's plan to spend more next year may end up delivering less than expected.

The data may not bode well for euro zone's economic growth prospects, as the bloc is facing risks of a protracted slowdown, which many economists say could be countered only with a significant increase in governments' spending - especially by Germany, the euro area's largest economy.

Eurostat said Germany's revenues last year exceeded expenses by more than previously estimated, allowing Berlin to post a budget surplus of 1.9% of its output, above the 1.7% that Eurostat had calculated in April.

The euro zone overall recorded a 0.5% deficit, unchanged from Eurostat's previous estimate as Germany was offset by higher-than-expected spending in other countries, such as Italy, which posted a 2.2% deficit, above the 2.1% estimated earlier.

The 19-country currency bloc's debt was revised up to 85.9% of gross domestic product from the 85.1% previously estimated.

The upward revision of Germany's budget surplus confirms the trend in surprise overshoots in data from Berlin. In 2017, the country's surplus was raised to 1.2% of GDP from the 1.0% initially estimated.

In 2016, the final surplus was recorded at 1.2% of output from 0.9% previously estimated.