PURPOSE: To attain retransmission without redialing by providing a dial information storage memory so as to read dial information with the hooking operation or trimeout of a timer when a called party is busy at the connection of outgoing call.

CONSTITUTION: When a handset is hooked off, a line A is connected to an outgoing register trunk ORT and when a called party number is dialed, the number is received at the trunk ORT and stored in a memory MM. A controller CONT is going to connect the extension A with the called party, and if the called party is busy, the extension A is connected to the outgoing register trunk ORT, a busy state timer is set. When the timeout occurs or the hooking or the like is operated before the timeout, the dial number stored in the memory MM is discriminated and the retransmission connection to the called party is attained.