The parties are yet to conclude binding agreements and to get board approvals.
Shares in Innogy were up 13.8 percent to 39.28 euros at 1025 GMT after Sunday's proposed deal from RWE and E.ON, which plans to offer Innogy's minority shareholders 40 euros per share, or 5.2 billion euros, a 16 percent premium to Friday's close.
But the heart of the agreement is to give E.ON the retail and network businesses of both companies, and give RWE the combined renewable-generation businesses. The shares would be issued by way of a 20% capital increase against a contribution in kind from existing authorised capital.
"Through the renewable pipeline, RWE, too, should be able to offset its dwindling nuclear and lignite business as well as attract partners for the expansion of its wind business".More news: Engine woes: Aviation watchdog grounds 11 Airbus planes of IndiGo, GoAir
The big six pair both shrugged off fears that a complex deal between German energy giants RWE and Eon, which emerged over the weekend, would derail their plans to create Britain's second largest energy supplier.
Share in Innogy, RWE, and E.ON all surged this morning as the markets responded positively to the news. The two retail operations would combine... Today it reported 2017 results, saying its adjusted net profit grew by 9% to more than Euro 1.22 billion.
The company is projecting overall adjusted EBIT of about €2.7 billion ($3.3 billion) and adjusted net income of over €1.1 billion ($1.36 billion). This price will again include Euro 3.24 in dividends.
Should the prospective deal go ahead - the acquisition still needs to be approved by European Union regulators and the companies' respective boards - it would represent a significant shift for both organisations and the German energy sector more generally. It also had 582 MW of onshore and offshore wind projects in construction.