The report said group member Kelly Rowland made the announcement on stage in Barcelona during the weekend.
The trio's "Destiny Fulfilled ... and Loving It" tour will hit North America beginning July 2 in New Orleans and wrap Sept. 10 in Vancouver.
The corresponding album, "Destiny Fulfilled," debuted at No. 1 on The Billboard 200 late last year and spawned the hit single "Lose My Breath." Nielsen SoundScan said the album has sold more than 2.7 million copies in the United States.
The group's other members are Beyonce and Michelle Williams.