Sources involved in the negotiation tell TMZ ... the deal was signed several days ago, and Britney is elated. Everyone involved in the concert is relieved Enrique Iglasias' ego couldn't handle opening for Britney and feel Nicki will be infinitely better.
Minaj, who is on tour with Lil Wayne until the end of the month, currently has two singles on the Billboard Top 100 -- "Moment 4 Life" and "Did It On'em"
Everyone connected with the concert series things Nicki will create even more heat for the tour, which kicks off on June 17 in Sacramento, CA.
TMZ broke the story Nicki and Britney were in serious negotiations. Right after we posted that story, the comments and emails were almost unanimous that Nicki is an infinitely better choice than Enrique.