The bulk of the money will be used to upgrade and expand the local gas and electricity networks, the company said.
E.ON reported consolidated sales of RON4.33 billion (about EUR1 billion) in Romania last year, close to the 2010 level.
The local units of the German group sold over 30 TWh of gas and electricity in 2011, slightly up on the year.
Since the beginning of its operations in Romania in 2005, E.ON has invested over RON1.9 billion on the local market.
Last week, the German utility announced plans to open a regional business service center in Cluj-Napoca city, northwest Romania, which is slated to create around 600 new jobs.
E.ON runs four companies in Romania, namely E.ON Energie Romania, E.ON Gaz Distributie, E.ON Moldova Distributie and E.ON Regenerabile Romania. The four companies employ 6,500 staff and serve together around 2.9 million customers. (EUR1=RON4.4641)