The Fort Worth-Star Telegram reported the Mavericks will receive Jamison, power forward Danny Fortson, small forward Chris Mills and guard Jiri Welsch from Golden State.
The Mavericks will send guard Nick Van Exel, center Evan Eschmeyer, forward Popeye Jones and veteran point guard Avery Johnson to Golden State.
The trade can't be approved until the NBA offices open Monday.
If the deal goes through, it would be a major move for the Mavericks, who failed to make a splash in the free agent market while the Los Angeles Lakers, Sacramento Kings and defending champion San Antonio Spurs all were active.
Dallas lost to San Antonio in the Western Conference finals last season.