The Gray administration has commissioned an Illinois firm with close ties to the charter school movement to study how D.C. neighborhoods are served by the public education system and help officials decide which schools should be closed and where new ones might be opened.

The study by the Illinois Facilities Fund is the strongest signal yet that Mayor Vincent C. Gray (D) is prepared to treat charter schools — which are publicly funded but independently operated — as full partners in a reform effort that was heavily focused on traditional schools during the tenure of his predecessor, Adrian M. Fenty (D). About 40 percent of the 75,000 D.C. public school students attend charter schools.

D.C. officials also will use the analysis, expected to be completed by mid-October, to guide what may be a significant round of school closures next year. The city has more than 40 traditional schools with less than 300 students apiece. Chancellor Kaya Henderson called the IFF study a potential “game changer” and acknowledged that it could lead to a smaller traditional public school system and further expansion of the fast-growing charter sector.

“If it helps us to better deliver on the promise of a great education for every child in every neighborhood in the city, I’m willing to change the game,” Henderson said Thursday. She succeeded Michelle A. Rhee last fall as head of the school system.

It will also help assess a proposal for a new middle school in Northwest Washington promoted by council member Mary Cheh (D-Ward 3).

IFF, a nonprofit organization based in Chicago, said it will conduct what amounts to a supply-and-demand analysis. It will look at the distribution across neighborhoods of seats in what it calls “performing” public schools — those that meet D.C. academic standards — comparing it with the population of school-age children in those areas. It will then rank neighborhood needs according to school performance, demographics, enrollment and building capacity.

It is a rare instance of the city forming educational plans by looking at both public sectors — traditional and charter — as one. Deputy Mayor for Education De’Shawn Wright, whose office is responsible for school facility needs, said he pushed for the study because the city needs a clearer picture of how it should proceed.

Wright also said he hoped to use the findings to guide decision-making by the D.C. Public Charter School Board, which authorizes the opening of charter schools.

“For the first time ever, we want to give them some front-line guidance about what the districtwide needs are,” Wright said. There are 53 public charter schools on 99 campuses, the heaviest concentration in any U.S. city outside of New Orleans. Thirty-six of the campuses are in Wards 7 and 8, east of the Anacostia River. Those communities also have most of the District’s lowest-performing and underenrolled traditional schools.

The study’s genesis could make it controversial in a city where public school advocates say that heavy private and corporate support for charter schools threatens to marginalize the 123-school public system.

The study’s $100,000 cost has been covered by the Walton Family Foundation, a leading charter funder, through a grant to the D.C. Public Education Fund, which raises private money for the city schools. The Walton foundation also is underwriting bonuses for D.C. teachers under the IMPACT evaluation system.

Wright said he requested Walton’s help because he had been impressed with IFF’s work in such cities as Kansas City, Milwaukee and Denver.

Founded in 1988 to offer financial support and real estate consulting to nonprofit groups, IFF has made more than $57 million in loans to charter schools, according to material it provided the District. In 2007, it received a $10 million federal grant to leverage charter school financing in Illinois, Iowa, Missouri and Wisconsin.

In 2004, IFF consulted with Chicago Public Schools — then headed by Education Secretary Arne Duncan — on the Renaissance 2010 project, designed to close underperforming schools and increase the number of good ones in underserved areas. IFF identified about 228,000 students in 25 Chicago communities shut out of “performing” schools. About 100 schools, roughly half of them charters, have been opened through 2010.

Some public school advocates question the choice of IFF to conduct the study. “What I would say is that it is not a strong choice for the deputy mayor,” said Mary Filardo, executive director of the 21st Century School Fund, which works for improvements in school facilities and planning. She described IFF as “a charter intermediary.”

“I really don’t understand why a foundation should be able to come in and define what needs to happen,” Filardo said.

Wright, a founding partner of the Newark Charter School Fund before his appointment by Gray, said he wasn’t concerned about IFF’s connections and was confident that its work would be objective. But he also echoed Henderson’s assertion that if the solution involved more charter schools, that was fine.

“I am very much wedded to quality, and I don’t care where it comes from,” said Wright. “And let’s be completely candid here,” he added. “We have to right-size the [school system], and we have to be honest about where we’re not providing high-quality schools to our children. And if that ruffles feathers, then so be it.”

Jose Cerda, IFF’s vice president for public policy and communications, also discounted concerns that it favors charter schools. “Almost every city we’ve been in, no one part of the system is the solution,” he said. “It would be a mistake to say this work is charter-centric.”