According to People, the two stars announced that they have separated.
"Nicollette Sheridan and Michael Bolton have amicably ended their engagement," stated Nicole Perna, the Desperate Housewives star’s rep.
"They appreciate your respect for their privacy in this matter," added Perna.
The couple have known each other for many years and started dating in the beginning of 1992. The 55-year-old musician and 44-year-old actress reunited in 2005, and announced their engagement in March 2006.