FRANKFURT (Reuters) - Companies interested in lighting assets will be able to bid for top European brands Philips (>> PHILIPS) and Osram (>> Osram Licht AG) in two separate auctions starting this month, industry sources on Friday.

Dutch technology group Philips (>> PHILIPS) has put its entire lighting arm on the block as the group focuses on its healthcare systems business.

While Philips has not yet decided whether to list the lighting business on the stock exchange or outright sell it, it has asked for tentative bids for the unit, which may be valued at roughly 4-6 billion euros ($4.36-6.53 bln) by the end of January, people familiar with the deal said.

A consortium comprising buyout groups KKR (>> KKR & Co. L.P.), CVC and Onex (>> ONEX Corporation) is expected to make an offer for the business, as well as peers like Bain, Apollo (>> Apollo Global Management LLC), Blackstone (>> Blackstone Group LP) and Chinese bidders, they said, adding that U.S.-based Acuity (>> Acuity Brands, Inc.) may show interest in parts of the unit.   

Separately, Philips last year agreed to sell its smaller Lumileds unit to Chinese investors in March. But doubts arose over the deal in October after a U.S. government body raised objections.

Now, Philips may have found a way to close that deal, a person familiar with the matter said.

A Philips spokesman said discussions with U.S. authorities are ongoing, and the closing of the deal is uncertain, declining to comment further on the two sales processes.

Separately, German peer Osram (>> Osram Licht AG) has asked for tentative bids for its traditional lamps business next week. Chinese buyers have expressed interest in the strong brands and distribution channels.

Bidders are likely offer to value the business at roughly 500 million euros ($545 million), the sources said. Chinese LED products maker MLS (>> MLS Co Ltd) is expected to make an offer, sources familiar with the deal said, as well as a consortium comprising Chinese group Foshan (>> Foshan Electrical and Lighting Co., Ltd.) and buyout group Bain.

Shanghai Feilo Acoustics (>> Shanghai Feilo Acoustics Co., Ltd), which said in July it already had made a non-binding offer, is no longer pursuing the asset, the sources added.

"The sales process is ongoing," an Osram spokesman said. The prospective bidders for Philips and Osram lamps businesses declined to comment or were not immediately available for comment.

(Reporting by Arno Schuetze; Additional reporting by Toby Sterling, Freya Berry, Matthew Miller and Jens Hack; Editing by Harro Ten Wolde and Katharine Houreld)