President Reagan's deep interest in the film and entertainment industry after a 40-year career as a radio announcer, actor, Hollywood spokesman and television host has cast him in a central role in the mounting dispute over ownership of television programming.

The dispute centers on the Federal Communications Commission proposal--endorsed by the Justice and Commerce Departments--to remove rules that prohibit the networks from owning and syndicating prime-time programming. Hollywood studios and producers who have thrived under the current system are fighting to retain the restrictions on the networks.

Administration officials are deeply divided over the issue--which is potentially worth billions of dollars to the winner--and although Reagan has not taken a public stand, privately he has made it clear that he has serious reservations about the power of the networks. That concern stems in part from his experience in Hollywood in the days when television producers had no outlets for their work other than the national broadcasters.

There is considerable evidence in the president's film industry background, for example, that he is concerned about film distribution and syndication patterns and the power of distributors--or, in this case, the networks.

In a letter to Lou Greenspan, executive director of the Producers Guild of America, cited in Helene von Damm's book, "Sincerely Ronald Reagan," Reagan complained about the nudism and vulgarity of the film industry in the '70s. Then he added:

"My other view is that the industry should start beating a path to Washington but not to go down the deadly road of subsidy, because if you do, you'll wind up with a senior partner, headquartered in Washington.

"No, what Hollywood needs is to eliminate the court decree in the early 1950s that separated production and exhibition. Hollywood should be allowed, like a candy store, to make pictures in the backroom and sell them in the front. That selling can be both theatre and a form of pay television where the theatre becomes the living room--something it has already become, but for bargain-basement entertainment."

White House officials say that in conversations about the dispute over the FCC rule, Reagan reaches back to his film-making days and his feelings about Hollywood.

Says one official: "The analogy that he's raised is that of the old movie houses--in the days of the chains--that the movie houses were exhibition halls for independent productions that encouraged competition and creativity. He's coming at it from this view: 'How do we encourage creativity?' He does not want to be a party to something that creates a monopoly."

Several officials said it would be incorrect to assume that Reagan is simply responding to the urgings of old Hollywood cronies. They said Reagan has talked privately about what one called "a concern that the networks might obtain a monopoly over the producers. He has a fear of increased concentration."

Nor, said a White House official, is the president motivated by resentment at network news coverage of his administration. Reagan has complained about TV coverage--chiefly of his economic program--but the official said, "I've never heard him go around here saying, 'let's get CBS.' "

Instead, this official said, Reagan "remembers how the networks dominated in the old days" and has "seen the producers flourish" under the existing arrangement. "It's natural for him to say, 'Why should we go back and create the old abuses?' "

Reagan has long held "serious reservations about the concentration of power in the networks," said another White House official. "That is his principal concern. He has been anxious to hear the arguments why this doesn't potentially further the concentration of power of the networks."

Another said Reagan sees the networks as being "all-powerful, not in a derogatory way, but from the point of view of a guy who is a little resentful."

It is a point of view that the networks realize they cannot change. "We can't do anything about it," said a top network official. "We might as well forget about converting him."

The networks do not have political action committees and fund-raising arms to match those of the Hollywood forces, which recently raised over $300,000 for the Senate Democratic Campaign Committee at two West Coast affairs. But network officials hope they can quietly sell the notion, as one put it, "that cronyism and big money are running the show."

The depth of Reagan's interest in the matter was signaled recently when he donated his residual payments from 52 films to charity so that he could participate without the appearance of a conflict.

But Reagan apparently did not air his views on the issue 10 days ago at a Cabinet Council meeting on legislation in the Senate to bar the FCC for five years from lifting the financial interest and syndication rules. (An appropriations bill passed by the Senate Thursday would delay the FCC move for six months.)

The White House meeting was held to decide on an administration stand on the legislation. The enthusiastic support that the Justice and Commerce Departments have given to the FCC plan, and the fact that the Reagan transition team had put lifting the rules atop its list of communications policy priorities, apparently have not closed the door on the subject.

Adding to the controversy is the decision by Rep. John Dingell (D-Mich.), the feisty chairman of the House Energy and Commerce Committee and its oversight and investigations subcommittee, to launch a staff investigation of whether there was anything improper about the Cabinet Council meeting or an Oval Office session earlier ago with FCC Chairman Mark Folwer.

Dingell is concerned that the Fowler meeting and Reagan's involvement in the issue improperly involves the White House in an issue before an independent regulatory agency. White House officials say that the Fowler meeting was a briefing and that Reagan gave the FCC chairman no instructions on how to handle the issue.

Jack Valenti, president of the Motion Picture Association of America and a leader in the effort to block the FCC action, said Reagan "would be derelict if he didn't get involved" in the dispute. "99.9 percent of the people in this government have no knowledge of what goes on in television. This is more important than anything except war and peace and the family pocketbook," Valenti said.

On the other hand, William Lilley III, corporate affairs vice president at CBS Inc., said it is "incomprehensible and unbelievable" that the Cabinet departments would change their views, stated in FCC filings, when the Senate Commerce Committee opens hearings on the matter Wednesday.

To understand how Reagan has benefitted from the power of television, it helps to recall his view of the presidency. He has often echoed Theodore Roosevelt's description of the office as a "bully pulpit," and one White House official who has spent years with Reagan said the president has an abiding faith in his own ability to use television to get his point across.

In fact, this official says, when he faces a major political problem, Reagan's reaction is often to suggest to aides that he give a nationally televised speech to solve it. This aide said he's heard Reagan say many times, "If I could only give a speech . . . "

And his career is peppered with examples of such speeches. The 1964 speech, "A Time For Choosing," that was made in the closing days of the Goldwater campaign, launched his political career. Reagan made a similar half-hour televised appeal in the final days of his own 1980 campaign; he turned again to television to push the Congress for passage of his tax and budget packages in 1981. Only last Thursday he went on the air to defend the use of American forces in Lebanon and Grenada.