Singapore Telecommunications has won a bidding battle to buy Cable & Wireless Optus, a subsidiary of Britain's Cable & Wireless and Australia's second biggest phone company.

Vodafone is telling Australian regulators it will transfer some customers to a competitor as part of its bid to acquire Cable & Wireless Optus.

Vodafone says it is making an indicative proposal to buy Australian firm Cable & Wireless Optus (CWO) in order to expand its presence in the country.