FRANKFURT, Aug 14 (Reuters) - Private sector investments

in Germany's electricity networks must be incentivised by better

returns, the chief executive of utility E.ON,

Europe's leading operator of energy networks, said on Wednesday.

"Grid operators now need a long-term, but quickly effective,

framework with provisions for adequate interest on spending on

existing and new networks," CEO Leonhard Birnbaum said in an

online call after presenting financial results for January

through June.

"Otherwise, the energy transition with millions of

decentralised units and protagonists will fail," he added,

referring to small wind and power generation plants.