UPDATE 1-Siemens Turkey says to make 1 bln euro investment

(Adds details, background)

ISTANBUL, March 21 (Reuters) - The Turkish unit of German engineering group Siemens (SIEGn.DE) will make investments of 1 billion euros ($1.55 billion) over the next four years, Siemens Turkey general manager Huseyin Gelis said.

The investments will include the construction over three years of a 200 million euro electricity distribution equipment factory in northwestern Turkey, Gelis told reporters on Thursday evening.

Siemens Turkey achieved sales of 2.5 billion euros in 2007.

"We are aiming for 4 billion euros in sales by 2010. Along with our factory investments, we are also thinking of inorganic growth, buying possibilities," said Gelis.

He said 45 percent of the company's investments would be devoted to energy, which along with industrial systems and medical devices is one of its three main areas of activity in Turkey.

"We have identified Turkey for Siemens as one of three countries in Europe requiring investment. We believe in the growth potential of Turkey," Gelis said. (Writing by Thomas Grove, editing by Will Waterman)