German retail sales rose at the fastest pace since June 2011 in September on a monthly basis, increasing by 1.5 percent in real terms, preliminary data showed on Friday, boosting hopes private consumption will remain a pillar of support for the economy.

The rise was stronger than even the highest forecast in a Reuters poll of economists' forecasts ranging from -0.4 percent to 0.8 percent, with the consensus estimate at 0.3 percent.

The notoriously volatile indicator was however down 3.1 percent on an annual basis, largely because shops were open one day less in September this year.

(Reporting by Alexandra Hudson and Sarah Marsh)