Jon Hamm, Jennifer Westfeldt announce separation

Los Angeles: "Mad Men" actor Jon Hamm and actress Jennifer Westfeldt have announced their split after 18 years of togetherness.

The pair, who began dating in 1997 and starred together in the 2011 film "Friends with Kids", gave no clue on the reason that prompted their break-up, reported People magazine.

Despite their separation, the celebrity couple stated they 'will continue to be supportive of each other in every way possible moving forward.'

"With great sadness, we have decided to separate, after 18 years of love and shared history. We will continue to be supportive of each other in every way possible moving forward," they said in a joint statement.

Hamm, 44, and Westfeldt, 45, had been the subject of split rumours for months. Earlier this year, Hamm completed rehab for alcohol abuse and credited Westfeldt for supporting him throughout his treatment.

In April, the couple released a statement denying reports they had broken up. The actor and actress were last seen stepping out together on July 22 at the after-party for the "Wet Hot American Summer: First Day of Camp" premiere in New York City.