* En+ planning IPO, looking for cornerstone investors
* En+ manages aluminium, power assets of tycoon Deripaska
* CEFC bought $9 bln stake in Russia's Rosneft this month
HONG KONG/LONDON, Sept 12 (Reuters) - China's CEFC is considering investing in En+ as part of the aluminium-to-power conglomerate's planned IPO, industry sources said, potentially boosting Beijing's ownership of Russian natural resources.
If CEFC buys a stake in En+, it would be the second large deal by the fast growing Chinese conglomerate in Russia this year, following its purchase last week of 14 percent of Kremlin-controlled oil major Rosneft for $9 billion.
"CEFC is looking to further boost its presence in Russia and buy into En+," one of the sources told Reuters.
CEFC would buy into En+ as a cornerstone investor during an IPO scheduled for later this year, although the investment was conditional on the flotation going ahead, a second source said.
Oleg Deripaska, the main owner of EN+, is looking to raise money for investments and debt repayment.
En+, which manages Deripaska's aluminium and hydro power businesses, wants to raise about $1.5 billion from a possible IPO in London, Deripaska said in June.
However, the IPO was postponed after the United States imposed new sanctions on Russia in August.
En+ said its the parent company, Basic Element, had signed a wide-ranging strategic cooperation agreement with CEFC in July and the two firms were studying various forms of cooperation. It declined to discuss the IPO and stake sale plans.
A CEFC spokesman said he was not aware of such a deal and could not immediately comment.
Under the deal with Rosneft, the Russian oil firm has pledged to give CEFC access to its oil fields and petrochemical projects in East Siberia, not far from the border with China.
En+ also controls assets in Eastern Siberia, including utility EuroSibEnergo and 48 percent of Hong Kong-listed aluminium producer Rusal. (Writing by Dmitry Zhdannikov; additional reporting by Aizhu Chen; editing by Alexander Smith)