Shares in Cable & Wireless Worldwide jumped 18% on Thursday after Tata of India said it was evaluating whether to make an offer for the company.
The BBC reports Tata's expression of interest follows one from Vodafone in mid-February, which sent the shares 29% higher.
Vodafone has until 12 March to declare whether it intends to make an offer, while Tata has until 29 March.
At current prices, CWW has a market value of £900 million.
Tata has one of the world's largest undersea cable networks.
CWW specialises in networking and broadband for corporate clients, including Tesco and police in Britain.
Its share price has fallen sharply in value since it split from Cable & Wireless's telecoms arm in the Caribbean in 2010.
Chief executive Gavin Darby said last month that the company needed a new direction.
