Sony SPP-IM977 - Manual (Page 29)

Basics
Basics
29 US
Making another call while talking
Example: Making a call on line 2 while talking on line 1
1
Press (HOLD) while talking.
The line 1 is put on hold and the LINE 1 button flashes
slowly.
2
Press (LINE 2).
3
Dial a phone number for the second party.
Now you can talk to the second party on line 2.
4
To put on hold line 2 and resume the conversation on line 1,
press (HOLD), and then (LINE 1).
or
To disconnect line 2 and resume the conversation on line 1,
press (LINE 1).
Note
If you do not press (HOLD) in step 1, line 1 will be disconnected.
You can talk with two parties at the same time using both line 1 and
line 2, see “Having a conference call” on page 49.