FRANKFURT, Feb 8 (Reuters) - E.ON on Wednesday said the devastating earthquake in southern Turkey has affected the supply area of local power grid operator Enerjisa Enerji, in which the German group owns 40%, adding that repair work was currently underway.

"We are dismayed and saddened by the two major earthquakes in Turkey and Syria ... they not only caused great human suffering and many deaths and injuries, but also massive damage to the infrastructure," an E.ON spokesperson said in e-mailed comments.

"The supply area of our Turkish joint venture Enerjisa is also affected," the spokesperson said, adding the company mourned the loss of four employees while others were wounded, some in a critical condition.

Enerjisa, in which Sabanci Holding also owns 40%, has more than 10 million customers in 14 Turkish provinces, including Adana and the surrounding region, which are among the affected parts of Turkey.

Around 2,500 transformers - key components of long-distance power transmission - are still out of operation and 380,000 people are without electricity in Enerjisa's supply region, the spokesperson said, adding this was already down from 1 million shortly after the earthquake.

Repairwork has started, the spokesperson said, adding that technical teams from less affected regions were providing support. (Reporting by Christoph Steitz; Editing by Kirsten Donovan)