In a statement announcing their separation on Tuesday, Aguilera said the pair's commitment to their son "remains as strong as ever."
Aguilera cites irreconcilable differences for the breakup.
The couple has one son and they are seeking joint custody.
The entertainer's 1999 debut album, "Christina Aguilera," was a commercial success and included such hit singles as "Genie in a Bottle." But her latest CD, "Bionic," generated poor sales when released earlier this year.
The Associated Press contributed to this report.