* Bids value Addax at more than $8 bln -sources
* Both sides currently in negotiations -sources
* Takeover would provide exposure to Africa and Middle East (Adds background, details, quotes)
By Joseph Chaney and Michael Flaherty
HONG KONG, June 17 (Reuters) - China's Sinopec Group and Korea National Oil Co (KNOC) are competing to take over Switzerland-based oil and gas explorer Addax Petroleum, sources said, with bids valuing the company at more than $8 billion, including debt.
The takeover will provide the successful bidder with exposure to Addax Petroleum's projects in Nigeria, Gabon, Cameroon, and exploration licences in the Kurdistan region of Iraq.
An acquisition by Sinopec Group, the parent company of China's Sinopec Corp, or KNOC would fit with the two companies' strategy of securing energy assets to fuel their economies.
Both KNOC and Sinopec were negotiating with Addax, which has a market capitalisation of $6.1 billion, the sources said.
"KNOC has put in a bid for Addax -- for the whole company," a source with direct knowledge of the matter told Reuters.
All sources declined to be identified because they were not authorised to speak publicly about the matter. A spokeswoman for Sinopec said the company declined to comment when contacted by Reuters.
Credit Suisse is advising Sinopec and Bank of America-Merrill Lynch is advising KNOC, sources said.
However, a Seoul-based source with close knowledge of the deal said the Korean oil firm has doubts that its bid can compete with China's.
"KNOC said they don't have much chance with this one because the Chinese made a very attractive bid," the source told Reuters.
But last week Reuters reported that KNOC has hired six banks to arrange its debut dollar bond sale. The firm is an aggressive buyer of foreign assets as part of efforts by South Korea, the world's fifth-biggest importer of crude oil, to increase its reserves.
In February, Reuters reported that Addax has attracted buyout interest from multiple Asian suitors.
Addax has fields in West Africa, where Sinopec has interests, and in the semi-autonomous Kurdish region of Iraq, where KNOC is drilling for oil. (Additional reporting by Angela Moon in SEOUL; Editing by Jonathan Hopfner and Jean Yoon)