Like corporate executives fighting a hostile takeover, leaders of the International Typographical Union are resisting an unfriendly merger with the Teamsters union in a campaign that could go far toward shaping the future of organized labor in the newspaper and publishing industry.

The ITU leadership has the strong support of the AFL-CIO, a longtime enemy of the independent Teamsters. The labor federation prefers a merger of the ITU with two other AFL-CIO unions to form a 250,000-member organization that could enhance the bargaining power of the fragmented newspaper unions.

A key issue in the bitter merger campaign is the controversial reputation of the 1.9-million-member International Brotherhood of Teamsters. It was expelled from the AFL-CIO in 1957 in a dispute over union corruption and has fought frequent turf wars with AFL-CIO affiliates ever since.

Opponents of the merger describe the Teamsters as a corrupt, undemocratic union that would rob the ITU of its financial assets and its independence. Supporters say such criticisms are baseless, and that the Teamsters will reduce union dues and provide the clout needed to revitalize a sagging union.

A mail-ballot referendum will begin today, marking the latest chapter in a seven-year effort by the struggling ITU to find a merger partner to resuscitate a union that has lost more than half its members in the past 20 years, largely because of the automation that has revolutionized publishing.

The printers and mailers who make up the ITU -- 45,000 active members and 25,000 retired -- have prided themselves on running one of the nation's most democratic unions, which has long operated a permanent two-party system of "progressives" and "independents." Opponents of the merger portray the Teamsters as a model of an undemocratic union because their enormously powerful president and some other national officers are chosen by the union's executive board rather than by a membership vote and because members do not vote on such key issues as mergers.

The two sides, debating the issues at regional meetings and in costly advertising and public relations campaigns, have differed about the degree of autonomy ITU would enjoy under the merger plan. ITU would continue electing its own officers, but the Teamster president -- currently Jackie Presser -- would appoint a director who would oversee the ITU division of the Teamsters.

ITU's previous merger talks with two AFL-CIO affiliates, the 165,000-member Graphic Communications International Union and the 33,000-member Newspaper Guild, have collapsed for various reasons, including opposition by pro-Teamster forces. AFL-CIO President Lane Kirkland has tried for two years to shepherd the three into a single organization because the federation encourages mergers as the best means to combat employers, especially in industries where corporations are merging frequently.

The GCIU represents press operators, engravers and other production workers. The Guild represents news, advertising and clerical employes.

"The path for survival and prosperity for newspaper unions is to coalesce," said Guild President Charles A. Perlik Jr. "Our ability to gain a greater share of the wealth in this industry is directly related to our ability to get together. We will have a much stronger posture."

Two other AFL-CIO unions -- the International Association of Machinists and the Communications Workers of America -- have also expressed interest in merging with the ITU to form a giant newspaper union but are awaiting the referendum's outcome.

For the ITU, some industry observers see the current Teamster bid as a last chance for a 133-year-old union -- the nation's oldest -- to avoid extinction in an age of computerized typesetting and photocomposition.

"This is a move of desperation," said Charles Cole, labor relations consultant for the American Newspaper Publishers Association, "But I don't think the ITU is going to be a winner no matter which way the referendum goes."

The ITU has been unable to reverse its membership decline and may face new, deeper losses if members unhappy with the referendum outcome seek to disaffiliate and join other unions, Cole and other observers said.

The ITU represents workers in more than 500 workplaces across the nation and has 2,600 active and retired members in Washington. Its largest contracts here are with the Government Printing Office and The Washington Post.

Three of the five members of ITU's executive council oppose the Teamsters merger, including ITU President Robert S. McMichen, who calls the proposal a "nightmare that would destroy our union." McMichen and Vice Presidents Billy J. Austin and Bill Boarman urged ITU members and retirees to reject the Teamsters in a strongly worded appeal in the union's monthly magazine: "Corruption. Attacks on members. Dictatorial leadership . . . Every count in the moral and ethical indictment against the Teamsters' union flies in the face of what ITU has stood for since it was founded in 1852. To vote ourselves part of this swamp would be insanity."

But in the same issue of the magazine, the ITU's second-ranking official, Thomas W. Kopeck, and Vice President Allan J. Heritage, accused merger opponents of "misstatements and outright lies." They said the Teamster merger could be the ITU's salvation because it would become an autonomous division of the giant union, rather than being absorbed into a larger union, as other merger proposals have suggested.

"Do you want lower dues? Preservation of the identity of the ITU? More clout at the bargaining table? Vastly enlarged organizing programs?" asked Heritage.

Union dues are a key concern for ITU because its dwindling membership has forced dues increases to maintain a national staff. In some jurisdictions, the printers and mailers pay up to $50 per month in dues. The Teamsters have promised a reduction to $6.90 a month -- without cutting staff and services.

"In order to believe that, you have to trust the Teamsters," said AFL-CIO spokesman Rex Hardesty, "and a lot of good people at ITU don't."

"I don't understand this skepticism," said Teamster research director Mary Ann Keeffe. Other unions lack the financial resources to make such a pledge, she said, but the Teamsters "have built-in services and staff for organizing, legal services, negotiating. They automatically plug in to our benefits."

The ITU has a $350 million pension fund and more than $15 million in assets, including its Colorado Springs, Colo., headquarters complex and the nearby Union Printers Home, a retirement facility. The merger would transfer assets to the Teamsters, merger opponents said, and would make the pension funds "subject to the Teamsters investment philosophy . . . which is nothing to boast about" -- a veiled reference to previous problems, including organized crime's influence in pension investment.