Virgin Media has refused to comment on rumours it is to be taken under private control in a £5.5 billion takeover.
Media reports on both sides of the Atlantic state that the British communications firm is attracting the interest of private equity giant Carlyle.
Virgin Media, which is listed on the US exchange Nasdaq, has reportedly been made an offer of $33 (£16.50) per share.
On Friday shares at the company, which became the first in the UK to offer a quadruple-play deal of internet, satellite television, mobile and fixed-lined phone services, closed at $24.37 (£12.13).
Responding to news of a potential bid, a Virgin Media spokeswoman said the firm "did not comment on speculation".
If the deal were to go ahead, including the taking on of Virgin Media's £6 billion worth of debt, it would become the second-biggest private equity takeover of a British firm after Kohlberg Kravis Roberts assumed control of Alliance Boots.
Virgin Media, which has Sir Richard Branson as its largest shareholder, was formed un a union between NTL: Telewest and Virgin Mobile earlier this year.