BEVERLY — Mayor Bill Scanlon's pledge to withhold money unless the School Committee approved his plan might have drawn gasps and outrage on Tuesday night.

But according to the head of the Massachusetts Association of School Committees, Scanlon has the right to employ that tactic.

"The mayor was within his authority to tell the School Committee that, 'I'm not going to approve a higher budget than I have to if it doesn't look the way I want it to,'" Glenn Koocher said.

Koocher is executive director of the Massachusetts Association of School Committees, a private group that represents more than 300 school committees across the state. He said he was speaking in general terms about the relationship between mayors and school committees and not specifically about the situation in Beverly.

Scanlon told the School Committee that he would give the schools an extra $680,000 if it approved his plan to close McKeown School, as opposed to Superintendent James Hayes' plan to close both McKeown and Cove schools.

When School Committee President Annemarie Cesa asked Scanlon if he would allocate the money if the board chose Hayes' plan, Scanlon said no. The committee voted for Scanlon's plan, 5-2.

Koocher said that kind of tactic is seen often in towns, where the finance committee or town meeting controls the purse strings as the mayor does in a city. He said it's not unusual for town meeting members to say, for example, they'll give the schools extra money but only if they don't cut the hockey program.

Koocher added that stipulations such as the one made by Scanlon are not legally binding, however. Once the extra money is included in the school budget, the School Committee could decide to spend it any way it wants, he said.

The committee, however, would have to be "willing to accept the political implications" of voting for one plan and then implementing another.

Asked yesterday about denying money for Hayes' plan, Scanlon said, "I think the saving of a school is important, and I was ready to try to go the extra mile to do it."

Scanlon did not want to discuss his tactics further, saying those questions are moot now that his plan has been approved.

"The vote (Tuesday) night clearly defines where they want to go," he said.