Efforts to launch a joint study by the Republican and Democratic national committees of ways to curb independent campaign groups fell apart yesterday. Each party's chairman said he would take his own steps to investigate the influence of the groups that specialize in "negative campaigns" against incumbents.

The abortive effort began two weeks ago, when Republican National Chairman Richard Richards told reporters that groups like the National Conservative Political Action Committee (NCPAC) "create all kinds of mischief" and their negative campaigns could backfire by creating sympathy for the targeted liberals.

Richard's comments drew criticism from the conservative groups and were in effect repudiated by White House political counselor Lyn Nofziger, who said the independent groups "on balance" help the administration by creating "a climate of doubt" about liberals.

But in the meantime, Democratic National Chairman Charles T. Manatt wrote Richards, inviting him to a bipartisan study of all kinds of iindependent political groups.

Yesterday, Richards replied that if Manatt wanted "to simply investigate independent expenditure groups, we are not interested," but would join in what he called "a joint effort to study election reform across the board." Manatt said he regretted Richard's decision, but said they might "find common ground" in "separate efforts."