Senate version of aid to the `contras'

1. $25 million of the $100 million aid package would go immediately to the Nicaraguan ``contras'' to acquire food, medical supplies, other nonlethal necessities, and ``defensive'' antiaircraft missiles. 2. $75 million would be held up for 90 days, during which time the Reagan administration would seek a negotiated solution to the Nicaraguan conflict.

3. If, after three months, the President determined ``there is no reasonable chance for negotiations,'' he would notify Congress of his intention to provide the $75 million in military aid.

4. Congress would have 15 days to block release of the military aid through a joint House-Senate resolution. If the President vetoed it, that veto could be overridden by a two-thirds majority of both chambers.

A House vote on the contra aid package is scheduled for April 15. If the aid measure is approved by the House, the 90-day clock on military aid will start as soon as President Reagan signs the bill.