Maryland Gov. Martin O'Malley proposed $336 million for school construction on Monday, with most of the funding going to build new schools or expand existing ones that are so packed that students are often forced into trailers.

O'Malley's proposed construction budget for fiscal 2014

contains $325 million for the Public School Construction Program, $300 million of which would be used for anything from building new schools and adding to existing facilities to making technological improvements. $25 million would be used for air conditioning in schools.

O'Malley spokeswoman Raquel Guillory said the proposed funding can be used for any school construction need, but the money hasn't been allocated to specific projects yet. Until lawmakers approve a budget this spring, it isn't certain which schools will get a cut of the $336 million.

Guillory said many students in schools that are old or beyond capacity are learning in portable trailers pulled onto school grounds.

"In 2006, [Lt. Gov.] Anthony [Brown] and I visited temporary learning shacks where there should have been modern classrooms and pledged to do everything in our power to put our children in state-of-the-art, 21st-century schools," O'Malley said.

A 2004 commission headed by state Treasurer Nancy Kopp found a "crisis" in public school facilities, with crowded classrooms, crumbling buildings and an abundance of portable trailers used to teach the overflow of students. The commission found students in functional buildings scored higher on standardized tests than those in poor buildings. It recommended $250 million annually go to school construction.

O'Malley's proposal also includes an additional $6.1 million to repair aging schools and $4.5 million in bonds.

The $336 million is 4 percent less than the $349 lawmakers approved for the current fiscal year.

Adam Mendelson, a spokesman for the Maryland State Education Association, said school construction is a "vital investment" and applauded O'Malley for proposing funding above the commission's recommendations.

O'Malley successfully pushed for a tax increase last year on Maryland residents earning more than $100,000, in part to help pay for record school spending.