CONCORD — House and Senate negotiators have reached a tentative agreement on a new school building-aid system that ranks projects to determine districts that will receive funding.

Currently the state has a moratorium on new school building projects, which has slowed approval of new projects at the local level.

The major differences between the Senate and House versions of the bills — a $50 million annual cap and a graduated percentage of aid based on need and financial conditions — have been resolved.

The Senate agreed to the cap, and the House agreed to graduated aid from 30 to 60 percent proposed by the Senate, although the Senate range would have been 20 to 80 percent.

Currently the state is obligated to pay about $550 million on more than 350 building projects over the next 30 years.

The ranking system would use such criteria as unsafe conditions, obsolete facilities, and overcrowding to determine which projects the state will fund.

The program would not begin until the next biennium, which begins July 1, 2013.