Two highly successful Bronx charter schools are suing the city because they haven’t been given promised space for expansion.

Icahn Charter Schools 6 and 7, affiliated with a charity funded by billionaire businessman Carl Icahn, requested additional co-location space inside public school from the Department of Education in July, according to the two Manhattan civil suits.

Education officials replied in December that they would pass along the request to the Panel for Educational Policy and recommend that it be granted, the suit says.

But the charters, which belong to a network of Icahn schools where students receive top scores in math and reading, still haven’t learned when, or if, they will move.

“Despite the passage of five months from the July 24 request, the DOE has not offered any specific space for the expansion of Icahn Charter,” a suit says.

The delay breaks state law, which requires the DOE to either provide charters with free co-location sites within a public school or pay for a private facility within five months of a written request, according to the Jan. 16 filing.

The suits say the Icahn network was also told it would receive any educational- impact statement and building utilization plan, but there’s no sign of either document. The charters are demanding space now or $2,800 for each pupil.

Icahn Charter School 6 currently serves K-4 and plans to grow to K-8 by 2019. Then it will have 324 students. Icahn Charter School 7 has the same plan, but so far includes only K-3. Next year, both schools will add a grade.

Both charters currently share space with conventional public schools. No. 6 is housed with PS-MS 4/the Crotona Park West and the Leadership Institute high school in Tremont. No. 7 operates out of PS 093/thr Albert G. Oliver School in Soundview.

The Icahn network’s highly competitive admittance rate — 4 percent — rivals Ivy League colleges.

Its mission is to “arm students with the skills and knowledge to participate in the most rigorous academic environments.”

The Icahn schools are pioneers in the city’s charter system.

An Icahn rep said the network is working with the Education Department to find appropriate space, but filed suit in case the move doesn’t go through.

A DOE spokeswoman said, “We determined that we would be able to offer co-located space to Icahn Charter School 6 and 7 and we still intend to do so. Icahn’s preserving its right of appeal is a pro forma legal move.”

A spokesman for the city’s Law Department said, “We will review the lawsuits.”

Additional reporting by Aaron Short