Wireless carrier AT&T Inc and fund manager BlackRock Inc are forming a joint venture to operate a fiber-optic platform in the United States, the companies said Friday.

The venture, Gigapower LLC, plans to deploy its network to an initial 1.5 million customer locations outside of AT&T's traditional 21-state wireline service presence, they said.

The companies said they would jointly own and govern Gigapower, but did not disclose additional deal terms.

The news comes as AT&T plans to expand its high-speed home internet service to newer areas in the country, in a bid to attract new subscribers.

Bloomberg News reported in October that AT&T had hired Morgan Stanley to help bring in an infrastructure partner to the venture, which could be valued at $10 billion to $15 billion.

AT&T did not immediately respond to a Reuters request seeking more details on the deal, while BlackRock declined to comment.

AT&T plans to report consumer subscribers served through Gigapower in its operational results and said any impact on spending and free cash flow from the venture will be included in the forecast it plans to provide at its quarterly earnings next month.

BlackRock, which manages $313 billion in alternative investments that include private equity, real estate and credit, has signed the deal via a fund in its diversified infrastructure unit.