First-quarter adjusted earnings before interest and tax (EBIT) grew by 24 percent to 1.3 billion euros ($1.6 billion), beating the 1.2 billion euro average analyst forecast in a Reuters poll of banks and brokerages.

"The first quarter seamlessly continued our positive performance of last year. Our operating business is strong. We achieved significant growth by adding more than 50,000 customers in Germany," Chief Financial Officer Marc Spieker said.

E.ON said its German retail business was instrumental in lifting the segment's first-quarter profit by 23 percent to 392 million euros, beating the 377 million euros average analyst forecast.

Its shares were indicated to open 0.9 percent higher.

Under the complex plans to split up Innogy, which is majority-owned by RWE, E.ON will receive the unit's retail energy activities and networks business, spelling the end for the group as a generator of electricity.

In turn, E.ON will transfer Innogy's and its own renewable energy activities to RWE, along with a 16.67 percent stake that will make RWE the group's largest shareholders.

(Reporting by Christoph Steitz; Editing by Maria Sheahan and Subhranshu Sahu)