Without much notice, the federal government is moving toward the most sweeping change ever in the rules that govern ownership of the American news media.

This shift could reduce the independence of the news media and the ability of Americans to take part in public debate. Yet because of meager press coverage and steps taken by the Federal Communications Commission in its policy-making process, most people probably have no idea that it is taking place.

Having seen how totalitarian regimes moved the world to war through domination of their news media, the government during the 1940’s put restrictions on how many news media outlets one company could own, both nationally and in a single city.

Though those rules have been relaxed in the last 20 years, companies are still blocked from buying a newspaper and television station in the same city or from owning more than one TV station in the same market.

Three weeks after it proposed eliminating those rules, the F.C.C. released a series of reports about the current media marketplace. But the reports focused almost entirely on the economic impact of relaxing the ownership rules. They largely ignore the public’s interest in a diverse and independent press.

The F.C.C. argues that technologies like the Internet offer Americans access to more information than ever and thus worries about monopolies are unfounded. But studies also show that most Americans receive their news from a handful of outlets. Beyond this, much of what appears on the Internet is repackaged from those outlets. The number of operations that gather original news is small and now may become smaller.

The question of concentration is most acute at the local level. In most communities, even those with television and radio stations, the vast range of activities are covered by only one institution, the local newspaper.

What will happen to communities if the ownership rules are eliminated? Among the possibilities is that one or two companies in each town would have an effective monopoly on reaching consumers by being allowed to control the newspaper, radio, TV, billboards and more — with costly consequences for businesses that need those outlets for advertising. Such a monopoly on information would also reduce the diversity of cultural and political discourse in a community.

The precedent in radio is telling. Since the rules on ownership of radio were last relaxed in 1996, the two biggest companies went from owning 130 stations to more than 1,400.

The F.C.C. chairman, Michael K. Powell, has scheduled only one public hearing, in Richmond, Va., on the proposal, and the public comment period will close at the end of this month. It is a small and brief opportunity, but one that the public should seize if it cherishes an independent press.