Visibly annoyed with the ongoing discussions between MCI and Qwest, Verizon has threatened to withdraw its offer for the long distance company, which was previously approved by MCI's board of directors. "Qwest has submitted what we believe to be an inferior offer," Verizon said in a statement late Monday.

Late last week, Qwest upped its offer for MCI to $9 billion, a half-million more than its previous bid and $1.4 billion more than Verizon's latest offer.

The back and forth between Verizon and Qwest has gone on for over seven weeks, and Qwest announced Monday it had delivered a signed commitment to MCI, which appeared to be warming to the idea of a merger with Qwest.

In response, Verizon has issued a letter to MCI detailing the advantages its offer has over Qwest and warning that "numbers in the Qwest proposal mask a myriad of financial and operational risks."

Despite previously allowing MCI to continue talks with Qwest, Verizon's patience has ostensibly worn thin.

"If the MCI Board, capitulating to Qwest's artificial deadline, declares this bid to be 'superior,' it would seem to us that the decision-making process is being driven by the interests of short-term investors rather than the company's long-term strength and viability," Verizon said. "Should this occur, we would no longer be interested in participating in such a process."