By a razor-thin margin, the largest Presbyterian group in the United States rejected a proposal Thursday to divest from three companies that do business with Israel. Pro-Palestinian advocates vowed to try again.

The Presbyterian General Assembly voted 333-331, with two abstentions, to reject the divestment plan. A second vote instead affirmed a policy of investment in support of peace in Israel and the Palestinian territories. That proposal passed by a much wider margin, 369-290 with eight abstentions.

The votes came after days of discussion and more than two hours of floor debate at the meeting of the Presbyterian Church (U.S.A.) in Pittsburgh. The policymaking body will meet again on Friday, but there is little chance the divestment plan could be revived.

Divestment advocates said the targeted companies — Caterpillar Inc., Hewlett-Packard Co. and Motorola — profit from the occupation by providing bulldozers, surveillance technology and other products to the Israeli military.