(Adds E.ON comment, European Commission no immediate response, details)
BRUSSELS, July 12 (Reuters) - E.ON is set to win EU antitrust approval to buy rival Innogy's network and retail assets after the German energy group sweetened its concessions to address competition concerns, people familiar with the matter said on Friday.
The deal is part of a bigger asset swap with Innogy's parent RWE and will more than double E.ON's customers in Germany to nearly 14 million.
E.ON last month offered to sell part of its retail business in Hungary as well as Innogy's retail power and gas business in the Czech Republic with 1.6 million customers, after the European Commission voiced concerns that the deal may reduce competition.
The offer also included dropping 260,000 heating customers in Germany, as well as the right to operate 32 charging stations for electric cars along Germany's Autobahn motorway network.
E.ON subsequently improved its proposal for all three countries after the European Commission received feedback from rivals and customers, one of the sources said. The EU competition enforcer did not seek comments about the tweaks.
The Commission, which is scheduled to decide on the deal by Sept. 20, did not immediately respond to a request for comment.
E.ON said: "We continue to be confident to be able to close the transaction within the second half of 2019." (Reporting by Foo Yun Chee, additional reporting by Vera Eckert in Frankfurt; editing by Francesco Guarascio and Kirsten Donovan)