Westlife said they have split from their record label following a "breakdown of contractual negotiations".
The chart-topping boyband said they parted company with EMI Records "by mutual consent". They had released 2019 number one album Spectrum with the label.
In a statement, Westlife members Shane Filan, Markus Feehily, Kian Egan and Nicky Byrne said: "Due to a change of leadership and a breakdown of contractual negotiations, we have parted company with EMI Records by mutual consent.
"We enjoyed our time with the label and are very proud of the huge success we achieved together, including our no. 1 album Spectrum and were humbled to be the label's biggest selling UK signed artist of that year."
The band, whose songs include Flying Without Wings, World Of Our Own and If I Let You Go, said they are working on a new album due for release later this year.
They added: "This change now allows us to embark on a very exciting new chapter. The next 18 months is shaping up to be our biggest yet, including a groundbreaking global partnership which we will be announcing imminently."
Westlife also promised "our biggest ever world tour," saying it will "take us across 5 continents including a sold out Wembley Stadium and for the first time ever, we will be bringing our live shows to America".
The group, who reunited to celebrate their 20th anniversary in 2018, cancelled a tour last year due to the pandemic.
Spectrum was the band's 11th studio album, and their first since 2010 record Gravity, which peaked at number three in the UK charts.
Westlife have sold more than 55 million records.