Minority shareholders of Virgin Mobile could block a deal between the mobile phone operator and NTL, according to a Guardian report.

Shareholders representing 75% of Virgin Mobile would need to give their assent for any potential tie-up to be green-lighted. The paper reported on Tuesday that Virgin now fears that a deal to grant NTL the right to use the Virgin name could be "held to ransom" by Virgin Mobile's minority shareholders.

The board of Virgin Mobile has already blocked an offer from NTL worth 323p per share. With Virgin Mobile shares now up in the 380p area, it is expected that NTL will have to raise its offer to around 375p per share to get Virgin Mobile's shareholders on board.