Uplink control information transmission method, and a network node and a UE implementing the method are disclosed. According to an embodiment of the invention, uplink control information is transmitted from a UE to a network node by defining a set including at least one uplink component carrier being usable for carrier aggregation for the UE. For this set, a priority indication is assigned to each one of the at least one uplink component carrier included in the set. Then, if this set includes at least one uplink component carrier comprising an uplink shared channel, one of the at least one uplink component carrier comprising an uplink shared channel is selected for transmission of uplink control information in that uplink shared channel. Selection based on at least one of the at least one assigned priority indication, when selecting uplink component carrier, is disclosed.