The boards of directors at British telecommunications and cable operators NTL and Telewest have agreed a $6 billion merger of the two companies.

NTL is expected to pay more than $23 per share in cash and stock for Telewest, with about 70 per cent of the bid in cash, according to Bloomberg news.

A formal announcement from the companies could come as early as Monday, the report said. The two companies have been in talks for months.