He is not as flamboyant or politically motivated as were William Randolph Hearst or Joseph Pulitzer, but Allen Neuharth, chairman of the Gannett Corp, has emerged as the leading newspaper industry spokesman on the imporant press issues of our time because he speaks the language of the bottom line.

The tanned and confident Neuharth. 54, was clearly the star of the 93d annual convention of the American Newspaper Publishers Association this week, opening with the boldest speech in defense of the First Amendment to be delivered by a publishing executive in years.

His increasingly aggressive attitude was rewarded on Wednesday when Neuharth was re -- elected chairman and president of the 1,332-member publisher's group.

The newspaper industry is coming off an excellent year, and Neuharth and his chain are no small part of the reason for that success. Gannett's 78 newspapers spread over 30 states and two island territories are textbook examples of how to succeed financially in the newspaper business. Most are small, with the average circulation about 34,000, and almost all are extremely profitable.

So to the publishers of America. Neuharth is the likely candidate to be their spokesman, a role largely unfilled in recent years. Rather than using the political power of his newspaper as William Randolph Hearst once did. Neuharth has found his own credentials through the strength of another aspect of journalism: profits. In fact, the Gannett newspapers pride themselves on editorial independence from their chain. "All the parent company ever wants to know is how much we are making, and why we aren't making any more," says one Gannett editor.

And it is clear that with the growth of television and radio as news mediums, the role of the daily newspaper has changed. Smaller suburban newspapers that can give the local news that is frequently unavailable in brief broadcasts are replacing their big-city rivals with increasing frequency. More than 75 percent of the nation's 1,756 daily newspapers have circulation under 50,000, and the majority are now owned by chains such as Gannett orKnight-Ridder.

For Gannett, which is the leading chain in terms of numbers of newspapers owned, owning mostly medium-sized or small-sized monopoly newspapers has spelled success. Neuharth can testify to that success with first-hand knowledge: He was paid $815,514 in 1978, representing a 139 percent raise from the year before and making him the highest-paid newspaper executive in the country.

And in his new role as industry spokesman, Neuharth has become a media celebrity. Feature articles in the business and general press have hailed Neuharth's accomplishments, and he has met with or spoken to 57 different audiences in the past year alone. And he has taken his company into the forefront in such areas as minority hiring and the promotion of women to key management positions. Gannett has more women publishers then any other chain.

There are other indieations that Neuharth is thinking of increasing the visibility of his company. Last week, for example, he announced that Deputy White House Press Secretary Walter Wurfel will become Gannett's "director of information" here.

And efforts are being made to beef up the Gannett News Service, which serves the chain's papers with Washington news and occasional features from around the world.

"We are going after higher-class talent for, the news service," Neuharth said in an interview at the convention. "We are not likely because of the size of our newspapers to have any real prestige operations like the New York Times or Washington Post is, but we can improve our wire service, and hire a small number of top reporters to cover major issues."

There is little fear among Gannett editors that the company would reverse its policy of editorial independence for its papers. Why should there be a change, they ask. The company -- like the industry -- is doing very well financially.

Daily newspaper circulation is moving up again after a period of decline in the early part of this decade. Both Sunday and morning newspaper circulation set records in 1978, while evening circulation dropped for the fifth straight year.

Further, newspaper advertising revenues are climbing at an even faster pace than the gross national product, with total newspaper advertising volume increasing by 15 percent to $12.7 billion in 1978.

Still, the industry faces problems. Because of a strike that began last summer by workers on the West Coast, some newspapers are facing serious shortages of newsprint, and a few have been forced to cut back the circulation or size of their papers. That strike is just coming to an end now.

The industry, nevertheless, is predicting another record year in 1979, including another huge leap in advertising revenues to almost $14 billion annually. CAPTION: Graph 1, Daily Newspaper Advertising Volume; Graph 2, Daily Newspaper Circulation, The Washington Post; Illustration, no caption