Verizon Communications Inc said on Thursday it has a "reasonable basis" to believe Yahoo Inc's massive data breach of email accounts represents a material impact that could allow Verizon to withdraw from its $4.83 billion deal to buy the technology company.
Verizon offered to buy Yahoo for $4.8 billion in July, but the deal hasn't closed yet.
Yahoo confirmed in September that 500 million user accounts were compromised in what could be the largest data breach in history.
