In a closed session Tuesday, the two sides agreed on a financing package for a proposed 68,500-seat stadium.
City officials say details of the proposal will be released on May 29, before the June 2 City Council meeting.
Santa Clara residents will still get to decide on the agreement. A citywide vote is expected in March. An environmental-impact report must also be completed.
The 49ers announced more than two years ago they wanted to move to Santa Clara, saying they would like a new stadium built by 2014.
Copyright 2009 The Associated Press.