SoftBank Group Corp. is considering a plan to consolidate its Yahoo Japan internet business with the messaging service Line Corp.

Z Holdings Corp., a unit of SoftBank's telecom arm formerly known as Yahoo Japan, confirmed Thursday that it's in talks with Tokyo-based Line about a possible merger but said no final decision on a deal had been made. Line said separately it is considering such a merger along with other opportunities to increase value.

Shares in both Z Holdings and Line surged in Tokyo.