The employees of Siemens Energy had secured themselves inside the Baiji power plant located 200 kilometres north of Baghdad amid the rapid advance by gunmen of the Islamic State of Iraq and the Levant (ISIS), Spiegel Online reported on Tuesday.
"All German workers who had been trapped in the power plant in Baiji have since been taken to safety," a Foreign Office spokeswoman in Berlin told The Local.
There was no confirmation of other details of Sunday's operation, which reportedly involved an Iraqi military helicopter and a passenger plane chartered by the German company. The workers were flown to Erbil and Baghdad.
Siemens in February won a contract to perform service and maintenance at the 600 megawatt gas power plant in Baiji, a city of 200,000 people on the main road to Mosul.
The group, which also included nationals from other EU countries and India, had not been under danger of imminent attack.
But the German company asked media not to report the situation earlier to avoid drawing attention to the workers and risk their being taken hostage.
An initial evacuation attempt to reach Baghdad by road failed after the group's convoy encountered roadblocks and had to turn back, Spiegel reported.
There are an estimated 1,000 German nationals currently in Iraq. Germany last week called upon its citizens to leave several overrun and endangered Iraqi provinces as well as the greater Baghdad area.
As heavy fighting ensued between militants and Iraqi government forces 60 kilometres from the capital, US President Barack Obama said on Monday that up to 275 US troops were being sent to the country to provide support and security for US personnel and the American Embassy in Baghdad.
However, he ruled out the direct deployment of ground forces in fighting in the escalating conflict.