MCI

Set to 25 different clues across 35 published puzzles, most often “Sprint rival” — The New York Times, Monday, 21 May 2007.

3 letters

Every clue on record, most used first

Sprint rival6 times
The New York Times — Monday, 21 May 2007
Long-distance letters2 times
The New York Times — Wednesday, 28 March 2007
Long distance letters2 times
The New York Times — Monday, 7 April 2003
Worldcom partner2 times
The New York Times — Friday, 20 April 2001
AT&T competitor2 times
The New York Times — Friday, 24 March 2000
AT&T rival2 times
The New York Times — Wednesday, 8 March 2000
Former telecom giantonce
The New York Times — Wednesday, 20 July 2011
2006 Verizon acquisitiononce
The New York Times — Sunday, 9 January 2011
Co. bought by Verizononce
The New York Times — Thursday, 9 December 2010
Verizon acquisition of 2006once
The New York Times — Saturday, 14 August 2010
2006 Verizon purchaseonce
The New York Times — Tuesday, 4 August 2009
Telecom giant acquired by Verizononce
The New York Times — Tuesday, 16 June 2009