The Consumer Product Safety Commission rejected yesterday an immediate ban on three household items containing cancer causing asbestos and began instead a months-long proceeding that could lead to an evantual ban.

Ruby I. Compton, a lawyer for the Natural Resources Defense Council, Which sought an immediate ban, condemned the delay, calling it "terrible when you think of the exposure that could occur in the next six months to a year."

The commission's decision to use a more deliberate approach in banning the three asbestos items - plaster patching compounds, decorative fireplace ash and embers, and tremolitic talc - came on a tie-breaking vote by Commissioner Lawrence M. Kushner. He had been absent Thursday when the commission deadlocked 2 to 2.

The commission's action means there will be no requirement for dealers to buy back the asbestos-containing goods from consumers, as there would have been under an immediate ban. "I'm disappointed," said Commissioner David Pittle of the 3-to-2 vote. Pittle had joined with Thaddeus Garrett in favoring immediate action while Chairman S. John Byington and Barbara Franklin formed a majority with Kushner.

Byington and Franklin argued that the slower process would better withstand legal challenges and thus may take less time in the long run. The minority wanted an immediate halt to sales and a repurchase program as an effective way of getting the goods out of homes and stores.

A commission lawyer said yesterday that at any time the commission can change its mind and seek an immediate ban.

When inhaled or ingested, asbestor can cause cancer, including mesothelioma - a cancer of the body cavity lining that is always fatal. Once taken into the body it remains, and there is no known safe level for asbestos in the body.

Not all products like spackling compunds contain asbestos, but Compton said it is hard to tell which do, for lack of labeling. The commission has ordered a broad staff study to determine the extent of asbestos in consumer goods, a move that could lead to a general ban.