Those with knowledge of the deal say that Verizon and AT&T will offer $3.93 a share for Vodafone's stock which would be a 40% premium to the current value of the shares. According to the source, Verizon would acquire the 45% stake in the company owned by Vodafone and AT&T would get the operations outside the U.S. Vodafone currently has 403 million subscribers and operates globally with a focus on Europe.
If the rumor is true, it would mean that all four major U.S. carriers would be involved in a deal at the same time. The third largest carrier, Sprint, is looking to close a deal that would see 70% of the company purchased by Japan's Softbank. Number four T-Mobile is a stockholder vote away from closing its deal to purchase number five MetroPCS. The latter's stockholders are voting on the deal next week.
source: FinancialTimes (subscription req'd), GIGaom via CNET