"The task order for security operations of Blackwater in Baghdad comes to an end today," and security firm Triple Canopy would replace it, embassy spokeswoman Susan Ziadeh told reporters.
Ziadeh said that "Blackwater has other task orders elsewhere in the country."
Blackwater guards killed 17 Iraqi civilians and wounded around 20 others in September 2007 in Nisour Square of western Baghdad.
Investigation later said that Blackwater guards excessively opened fire with automatic weapons while escorting an American diplomatic convoy through the square.
