Denver Public Works on Friday restarted the bidding for the Colorado Convention Center expansion project, three months after the city put things on hold when it found the process was tainted.

A press release from Public Works said the department sent out a new request for services including project management, design management, logistical coordination and evaluation of bids for the estimated $233 million project.

Mayor Michael Hancock halted the search for a contractor in December. His administration terminated its contract with Trammell Crow, who had previously overseen the bidding process. The city attorney found evidence that city documents were improperly released and approved plans were altered. Friday’s release said the misconduct “compromised the competitive bidding process for a design/build contractor.”

The massive project will include a rooftop expansion adding a 50,000-square-foot outdoor terrace and adding 80,000 square feet of new ballroom or meeting space.