Many major building projects in Tel Aviv have been delayed or altered due to a Defense Ministry secret communications channel, and contractors have been forced to develop shorter towers with less space and even help cover the cost of changing the defense establishment's infrastructure as a result.

One recent example is a a 20-story office building on Tel Aviv's Hamasger Street. The project, unveiled to great fanfare last month, may have to be scaled back or changed significantly to avoid disrupting the secret military communications network.

Defense Ministry approval is a precondition for obtaining construction permits. Developer Azouri Brothers, controlled by Ronen and Alon Azouri, is working to secure that nod. They recently began marketing the building's top floors, eight through 20, and say that occupancy is scheduled for January 2011.

The project is part of the municipality's plan for the area, which includes buildings of between 15 and 26 stories. It will join two recent additions to the area's office space, one building of 16 floors and a second with 26 stories.

A 30-story office building is also planned for an adjacent site.

Defense Ministry approval for the project is not assured, however.

Judging by the experience that other builders have had involving the Defense Ministry's communication system and the ministry's demands in the greater Tel Aviv region, Azouri Brothers may have to pay the ministry for the expenses involved in modifying the broadcast network in the vicinity of the new building.

They also may be forced to reduce the height of the building, altering the building itself and halting the construction of the uppermost floors until a solution is in place.

Details on locations within Tel Aviv that are affected by the Defense Ministry network are classified. Ministry and city officials have declined requests for information.

However, TheMarker has compiled a list of projects where this problem surfaced.

The issue has affected plans for many large projects in the city, including the high-rise complex in the works for the open space in the center of Kikar Hamedina. In that case, the developers, who have the city's support for the construction of a 43-story building on the site, may have to pay NIS 10 million to either relocate or bury part of the communications system.

The problem led to the scrapping of plans by the U. Dori Group to build two apartment buildings of between 8 and 11 stories, with a total of 74 residential units, on the northern edge of the city. The project had already received the municipality's approval. Instead, a single 12-story building with 60 apartments will be erected.

The Tel Aviv, Herzliya and Netanya municipalities have all faced problems with construction projects as a result of the Defense Ministry system.

The cost of burying the entire system underground has been estimated at NIS 55 million. Three months ago the Tel Aviv city council voted to allocate NIS 40 million for the relocation. Netanya has said it would contribute the remaining NIS 15 million.

"For almost every tower [built] in Tel Aviv, we get a request from the Defense Ministry" regarding its communication system, architect and city planner Moshe Tzur said. "By a rough estimate, the proportion of high-rise buildings in Tel Aviv that encounter problems with the beams comes to about 50%.

"We encountered a similar problem at the Bayside [Gav-Yam] center in Herzliya. There, we built up to the limits required by the beam - eight stories - instead of eleven stories as originally planned."

He said he often holds complicated and lengthy negotiations, lasting as much as two years, with the ministry over this issue, which he called "an important factor" in developing land.