Three ministries plan to set up a joint panel later this month to compile a package of case studies on measures to reduce the so-called "heat island" effect in which temperatures are higher in the middle of a big city than in surrounding areas, government officials said Sunday.

The Environment Ministry, the Land, Infrastructure and Transport Ministry and the Economy, Trade and Industry Ministry expect the package to encourage local governments and building constructors to adopt the measures, the officials said.

Given the new initiative, the government will postpone for the time being a plan to compile a policy outline to solve the problem. The plan was endorsed at a Cabinet meeting in March as part of a new three-year package of deregulatory measures.

"We don't have sufficient data, including analysis of the phenomenon and possible effects of individual measures such as water-permeable pavements," an infrastructure ministry official said.

On the panel, the infrastructure ministry will take care of such steps as energy-saving measures for office buildings and condominiums, water permeable pavements and the reduction of heat from vehicles.

The ministry will also consider steps such as a network of waterways and areas of greenery to ease the problem.

The industry ministry will deal with energy-saving and other measures for factories, while the Environment Ministry will assess the possible effects of the measures and try to determine what causes the phenomenon, mainly by analyzing data the Japan Meteorological Agency has amassed over the last 100 years.