The head of Colorado's health insurance exchange will leave in August to take a job with Cigna.

Patty Fontneau, who helped create Connect for Health Colorado and who oversaw the exchange's opening on Oct. 1, 2013, will become the presidnet of private exchange business for the massive health insurance company.

In a statement announcing her departure, Fontneau said she was proud of her success at the exchange, touting having opened it on time and under budget.

In her time at Connect for Health Colorado, Fontenau oversaw the enrollment of more than 140,000 people - an experience that garnered far better reviews than the exchanges of many other states and its federal counterpart, healthcare.gov.

She drew criticism for seeking a raise in December, when a wave of people sought insurance enrollments and, at times, encountered website problems or issues in gaining federal subsidies due to cumbersome Medicaid forms. She ultimately was given a 2.5-percent raise in May, bringing her annual salary to $195,314, the Denver Post reported.

An interim chief executive will be named within a week by the exchange's board of directors, according to the exchange's statement. The board also plans to hire a professional firm to search for a more permanent replacement.