The three financial trade groups lobbying to repeal withholding on dividend and interest income made campaign contributions to more than 80 percent of the 334 members of Congress cosponsoring repeal bills, according to a study by Public Citizen's Congress Watch.

The study said that 231 of the 287 House members cosponsoring the legislation received a total of $563,115, an average of $2,438 each. During the past four years, 41 of 47 Senate cosponsors received $323,118, or an average of $7,881 each.

The American Bankers Association, the U.S. League of Savings Institutions and the Credit Union National Association have launched a massive lobbying effort across the country, urging savers to write their legislators to ask repeal of the interest and dividend withholding, scheduled to begin July 1.

The new law does not impose any new taxes. But, in an effort to reduce cheating by taxpayers, it requires institutions to withhold 10 percent of interest and dividends paid Congress Watch officials acknowledged that the mail campaign--probably the heaviest in history--is the main reason legislators are cosponsoring repeal bills.

The biggest senatorial recipient of campaign contributions from political action committees run by the three trade groups was Minority Leader Robert Byrd (D-W.Va.). Rep. Fernand St Germain (D-R.I.), chairman of the House Banking Committee, received $18,000 in campaign contributions from the three PACs. Rep. Norm D'Amours (D-N.H.), one of the leading House backers of the repeal legislation, received $11,750 in campaign contributions from them.