DWTS' Karina Smirnoff and Maksim Chmerkovskiy Split

Jordan Strauss/WireImage.comUs Magazine

Karina Smirnoff and Maksim Chmerkovskiy have called off their engagement, her rep confirms to Usmagazine.com.

Chmerkovskiy, 29, posted on Twitter Monday: "What was meant to be a 'life long book', turned into a 'chapter'.......and now that 'chapter' is finished...... Se la vie..."

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The professional dancers got engaged on New Year's Eve 2008 -- six months after Smirnoff, 31, split from Mario Lopez. They planned to wed next summer.

In June, Smirnoff opened up to Us about meeting with a wedding planner to map out the big day.

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"We're really excited," she told Us at the Russian Heritage Festival in NYC.

"I definitely want that fairy tale, big skirt ball gown," she sent on. "When else can you wear that?"

Chmerkovskiy competes with Entourage star Debi Mazar, and Smirnoff with Aaron Carter when Dancing With the Stars returns to ABC Sept. 21.

E! Online first reported the news.