A wireless terminal (1) is configured, when a plurality of hybrid automatic repeat request (HARQ) ACK/NACK bits corresponding to a plurality of downlink component carriers (DL CCs) configured in the wireless terminal (1) are transmitted on a single physical uplink control channel (PUCCH) on a single uplink component carrier (UL CC), to change a spreading rate to be applied to time-domain spreading of a plurality of modulation symbols generated from the plurality of HARQ ACK/NACK bits, depending on the number of the plurality of DL CCs or the number of the plurality of HARQ ACK/NACK bits.