The $27.5 billion acquisition of Alltel by TPG and Goldman Sachs this week ranks among the 10 largest transactions among U.S. carriers over the past 10 years.

Here is the Top 10 list and the years in which they closed:

AT&T/BellSouth -- $86 billion (2007). Ed Whitacre’s last official acquisition act before retiring. It closely followed SBC’s purchase of AT&T but dwarfed that deal.

SBC/Ameritech -- $56 billion (1999). The second fellow Baby Bell acquired by SBC, giving it the Midwest territory it now owns.

Bell Atlantic/GTE -- $53 billion (2000). The megadeal that formed Verizon.

AT&T Wireless/Cingular -- $41 billion (2004). This deal made Cingular the largest wireless operator in terms of subscribers.

Sprint/Nextel -- $35 billion (2005). Sprint’s response to the AT&T Wireless/Cingular deal.

Qwest/US West -- $35 billion (2000). Here was a rare case in which an IXC acquired an RBOC. The roles would reverse within 10 years.

Worldcom/MCI -- $30 billion (1998). Worldcom outbid BT for this prized long-distance competitor of AT&T.

Alltel/private equity -- $27.5 billion (2007). Alltel taken private to increase shareholder value. Will Sprint Nextel now become a target?

SBC/Pacific Telesis -- $16.5 billion (1997). SBC’s first purchase of a fellow Baby Bell, expanding its territory into California and Nevada.

SBC/AT&T -- $16 billion (2005). Baby Bell swallows Ma Bell. It was supposed to be like this but it resurrected and reinvigorated the beleaguered AT&T -- and kicked off the current megamerger wave.