Straight Path Communications said the unnamed multi-national telecommunications company that’s bidding against AT&T for Straight Path’s assets has increased its offer from $104.64 per share to $135.96 per share. This translates into a value of $2.3 billion, compared to its original offer that amounted to about $1.8 billion.

AT&T kicked off this bidding war for Straight Path in early April when it offered $95.63 per share, reflecting a value of $1.6 billion.

Although Straight Path is still not naming the bidder that’s competing against AT&T, Reuters reported that “people familiar with the matter” say it is Verizon.

At this time, Straight Path remains subject to the deal it initially struck with AT&T, but AT&T has just three business days to match or exceed the latest bid.

Under the agreement with AT&T, Straight Path would be required to pay a $38 million termination fee to AT&T if it ends the deal. However, the unnamed bidder has agreed to pay the termination fee in such event.

Straight Path’s stock is trading at about $157 today, compared to $125 on May 2 before this latest bid, and compared to $36 in early April before AT&T’s initial offer.

Whomever wins the bidding war could have an advantage in its efforts to build a 5G network. Straight Path owns 735 spectrum licenses in the 39 GHz band and 133 licenses in the 28 GHz band, known as the millimeter wave bands. The licenses cover the top 40 markets in the U.S.