Los Angeles - Grey's Anatomy star Patrick Dempsey and his wife of 15 years, makeup artist Jillian Fink, are divorcing.

The couple said in a statement to People magazine: "It is with careful consideration and mutual respect that we have decided to end our marriage."

"Our primary concern remains the well-being of our children, and we ask with profound gratitude that you respect our family's privacy at this very sensitive time."

Celebrity news website TMZ said Fink filed for divorce, citing irreconcilable differences, and is asking for joint custody of their three children aged seven to 12, along with spousal and child support.

The 49-year-old actor, who plays Dr Derek "McDreamy" Shepherd on the Grey's Anatomy medical series, is reportedly worth around US$40 million (S$53.7 million).

He is a car racing enthusiast and was in Daytona Beach, Florida, for a 24-hour racing event when his wife filed for divorce.

They married in 1999.