Rising foreign demand boosted Germany's key mechanical engineering sector in December, the VDMA industry federation said Tuesday.

The manufacture of machine tools is a key part of Germany's industrial and export performance.

In December, overall incoming orders rose by 13 percent compared with the same month a year earlier, VDMA said in a statement, with export orders soaring by 15 percent and domestic orders up by 8.0 percent.

Taking a three-month comparison to iron out short-term fluctuations, overall orders rose by 3.0 percent in the period from October to December.

Foreign orders increased by 4.0 percent in the three-month period while domestic orders stagnated, VDMA calculated.

VDMA's chief economist Ralph Wiechers noted that the strong December figure was boosted by the comparatively low level of big-ticket orders from the euro area a year earlier.

"At the bottom line, domestic and export orders both increased by 2.0 percent for the whole year, short of our expectations,'' Wiechers said.