Falls Church’s City Council wants to see whether a private or public utility, including Fairfax Water, would be interested in purchasing the city’s water and sewer systems, city officials said Tuesday.

In a unanimous decision, the Council late Monday agreed to issue a Request for Expressions of Interest to see whether an investor-owned or public utility would be interested in buying a system that generates about $20 million a year and serves 34,500 accounts. About 90 percent of those customers reside in Fairfax County, and any purchaser would have to take into account the long-running conflict over water service that has pitted the city against its larger neighbor because of them.

That conflict led to a decision by Fairfax County’s Board of Supervisors late last year to assume authority for water rates of all county residents, including those who receive their water from the city of Falls Church or other municipal systems. In amending its water ordinance, the county also claimed the right to establish exclusive service areas for Fairfax Water, the county-controlled utility that supplies most water in the county.

Fairfax County officals said they acted in the name of ensuring fairness for its residents who received water from municipal suppliers. In a dispute that has been going on for years, including court battles, some county residents who received water from Falls Church’s system complained that their water bills were much higher than neighbors who received service from Fairfax Water.

But municipal suppliers accused the Board of overreach, saying it’s not clear that the county has such powers, and some threatened legal action. The City of Fairfax filed suit against the county shortly after the new year began.

Falls Church officials, meanwhile, decided to see whether there were any buyers for a system that has been operating since since the 1930s as a first step to testing its options following Fairfax County’s move.

“Council has been considering the future of the water and sewer utilities for quite some time,” Mayor Nader Baroukh said in a written statement. “Seeking industry input is the next step in the orderly, transparent, and comprehensive process where Council will consider all options.” Interested utilities would have until March 2 to come forward. Any proposed sale would have to be approved by voters in a referendum.

City Manager Wyatt Shields said Tuesday said that exploring a possible sale is just one outcome under evaluation by city officials. So is the status quo. The Council also has authorized the city attorney to take legal action against Fairfax County, though nothing has been filed.

County and city officails have said previously that they would be interested in working out an amicable solution that might involve Fairfax Water’s taking over the city’s system.

“They’re on our mailing list,”Shields said.

An earlier version of this story inaccurately reported the defendant in the City of Fairfax’s lawsuit. The story has been corrected.