The shape of the television industry and the government structure that regulates it may change dramatically with the growth of direct satellite broadcasting (DBS), a Federal Communications Commission staff report concludes.

The report, part of the FCC's network inquiry, suggests that although the technology has been developed to set up a system of satellites to beam programming directly to home antennas, regulation in the United States and abroad will determine its growth.

If such a system were permitted to develop to its potential, "It would clearly present an alternative to the present television networks," the staff report says.

Publication of the FCC report comaes a Communications Satellite Corp. and Sears, Roebuck & Co. are negotiating a proposal to make a joint application to the FCC that would lay the groundwork for the first satellite-home broadcast system.

Although the FCC staff report says that both "national and international regulatory environments seem increasingly receptive" to direct broadcast satellites it isn't clear how the FCC will set up a regulatory framework for the new systems.

The FCC will face critical policy decisions about the technology when it receives the Comsat-Sears application. First of all, the commission will have to determine how much of the broadcast spectrum to allocate for the home service. Just as important, the commission has to decide whether to regulate DBS as a broadcast or common carrier service or a combination.

"These regulatory decisions undoubtedly will have an important impact on the competitive viability of DBS and, consequently, upon a potentially significant source of additional networks," the FCC's report said.

And the FCC could face many applications to offer the service in addition to the Comsat-Sears proposal. "The service would be sufficiently novel and unique that no single firm or type of business entity would appear as a potential entrant," the staff study says.

But even with entry regulations in hand, a variety of "antitrust, cross-ownership and multiple-ownership policies may prohibit or limit entry" by firms already in some facet of the communications business, the report notes.

Representatives of the broadcasting industry already have told the FCC that they have serious questions about both the legality and need for the Comsat-Sears type of broadcast service. The commission itself has raised similar concerns.

The issue is complicated further by American Telephone & Telegraph Co. being the principal supplier of microwave and cable interconnections for the nation's television networks.

The three mejor networks paid compaines about $55 million in 1978 for these interconnections, for example, with most of that money going to AT&T. The effect that direct satellite broadcasting to homes would have on AT&T also remains unclear.

Nonetheless, development of the direct satellite system potentially threatens the role of the conventional television networks perhaps more than any other technological advance, including cable.

Sateallites already are used widely to transmit radio and television tstations, cable networks and other broadcast-like services. But the satellite-to-home technology has the potential to revolutionize the industry.