Switzerland's Swisscom and Belgian state-controlled telecoms firm Proximus said on Friday that talks were under way on the sale of a majority stake in their venture whose equipment handles global calls, text and Internet traffic.

Swisscom may sell its 22.4% stake in Belgacom International Carrier Services (BICS), while Proximus confirmed separately it may reduce its nearly 58% holding in the BICS venture to 49%. Both said in statements that a transaction with potential investors is not assured.

South Africa's MTN Group Ltd, the largest mobile operator of Africa and the Middle East, is also a minority owner in BICS, whose telecom cables and satellites handle calls, text messages and Internet traffic across the world.

BICS revenue fell 3.4% to $1.3 billion euros in 2019, with operating profit also slipping, as the unit was hurt by erosion in BICS's traditional voice services.

"Swisscom confirms that the shareholders of BICS (Belgacom International Carrier Services) are exploring a potential sale of 51% of BICS's shares. As part of the potential transaction, Swisscom explores the sale of its 22.4% participation in BICS," said Swisscom, whose shares are nearly 51% owned by the state.

Reuters last week reported that non-binding offers are due next week on the sale of the majority BICS stake, with final bids likely around the end of August or September.

(Reporting by Michael Shields, editing by John Miller)