U.S. private-equity company Harbinger Capital Partners, which for more than a year has been considering a purchase of mobile satellite services operator Inmarsat of London to combine with Inmarsat competitor SkyTerra of the United States, is purchasing the 52 percent of SkyTerra that it does not already own, SkyTerra announced Sept. 23.

The transaction, for $5 per share of SkyTerra stock, is expected to close late this year or early in 2010. It has fueled speculation of what Harbinger wants to do with its investment — not only in SkyTerra, which it will now own outright, but also in Inmarsat, of which it owns some 28 percent, and in TerreStar Networks, in which it holds a large minority stake. Unlike Inmarsat and SkyTerra, which operate in the L-band portion of the radio spectrum, TerreStar operates in S-band.

TerreStar has launched its large satellite and has committed funds for a second one. SkyTerra’s two large satellites are scheduled for launch in 2010.

Further complicating the U.S. mobile satellite services sector is EchoStar, which invested alongside Harbinger in TerreStar and is now active in the Chapter 11 bankruptcy proceedings of ICO North America, a startup mobile satellite services operator whose large S-band satellite was launched 18 months ago and has made no visible progress on its business plan.