Yahoo stock is sliding after Reuters reports Verizon's general counsel commented that there is a  "reasonable basis" to believe Yahoo email data breach had a material impact on deal.

Verizon Corp's general counsel, Craig Silliman, said on Thursday the company has a "reasonable basis" to believe that Yahoo Inc's massive data breach of at least 500 million email accounts represents a material impact that could allow Verizon to withdraw from its $4.83 billion deal to buy Yahoo.

Silliman told reporters that the data breach could trigger a clause that could allow Verizon to withdraw from the deal. "I think we have a reasonable basis to believe right now that the impact is material and we're looking to Yahoo to demonstrate to us the full impact. If they believe that it's not then they'll need to show us that," he said, declining to comment on whether talks are under way to renegotiate the purchase price.

And YHOO stock is slipping...