Panasonic KX-TD500 User Manual page 224

Station Features and Operation (PT/SLT)
To leave a 3-party conference
PT and SLT
Hang up or press SP-PHONE.
The other two parties may continue their conversation.
If both other two parties are on outside lines, they will be disconnected.
To terminate one party and talk to the other
PT
(CO) INTERCOM
or
Press the CO or INTERCOM or DN
of the party to remain connected.
A conversation with the desired party is established and the other party is
disconnected.
This operation is available only when the extension user established the
conference call by using two different line access buttons.
(Not available when only one button is used.)
To talk to the third party while holding the original party
PT
TRANSFER
Press TRANSFER.
If both other two parties are extensions, the INTERCOM
or PDN indicator light flashes green moderately.
224
(DN)
or
Confirmation tone
(optional)
Confirmation tone
(optional)
Talk.
Talk to the third party.
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