Clearwire (CLWR) is poised to receive another $1.5 billion from Sprint Nextel (S) and its partners as the wireless broadband company struggles to complete the first “4G” mobile high-speed network, The Wall Street Journal reported.

Sprint plans to invest $1 billion more in Clearwire while Comcast (CMCSA), Intel (INTC), Time Warner Cable (TWC) and Bright House Networks would inject another $500 million, the paper reported. However, search titan Google (GOOG) wouldn’t invest any more money in the joint venture.

The latest cash injection for Clearwire comes just 18 months after the joint venture set out to build its next-generation network, which is aimed at moving mobile data at very high speeds.

Clearwire’s stock jumped 4% to $6.75 on the news. Sprint, which is relying heavily on the joint venture, saw its stock climb 4% to $2.97.