Des Moines-based cable company Mediacom is threatening legal action against the city of Iowa City over its recently approved agreements with Cedar Rapids-based ImOn Communications, reports DesMoinesRegister.com. Mediacom alleges the agreements put it at a competitive disadvantage and company representatives on Monday delivered to the city a letter of complaint and a copy of a federal lawsuit they said they plan to file if city officials do not reconsider three agreements with ImOn. ImOn plans to bring Internet and phone service to Iowa City and to build out its service over the next five to 10 years.