At 1st level, you can attempt to gain control over a summoned creature by disrupting the bond between it and the caster who summoned it. You must make a caster level check (1d20 + caster level) equal to 10 + the summoning caster’s level. If you know the summoned creature’s name, you receive a +2 circumstance bonus on the check. If the check is successful, you can control the summoned creature as if you had summoned it for a number of rounds equal to 1/2 your wizard level (minimum 1 round). This does not increase the duration of the original summoning. The original summoning caster can attempt to regain control of the summoned creature as a standard action by making a caster level check against your caster level + 10. When your control ends, the creature reverts to the control of its summoner.
At 9th level, you can use this ability to bargain with called creatures as if you were the caster who conjured them. You can use this ability a number of times per day equal to 3 + your Intelligence modifier.