After years of hearing no, Vietnam veterans with a rare cancer they believe was caused by the defoliant called Agent Orange finally heard yes from the federal government.

For the first time, more than 1,600 Vietnam veterans suffering from non- Hodgkin's lymphoma - or their survivors - will receive compensation from the Department of Veterans Affairs, VA Secretary Edward J. Derwinski said."It is my hope that this action will help begin to mend the divisiveness and controversy that has surrounded this issue for many years," Mr. Derwinski said. Benefits would cost the government between $20 million and $23 million the first year, rising by another $2 million each succeeding year, agency officials estimated.

But while veterans and their advocates applauded the decision - approved by President Bush on Thursday morning, Mr. Derwinski said - they complained that it leaves more than 30,000 Vietnam veterans with other suspected Agent Orange injuries out in the cold.

"It's a step in the right direction. It certainly doesn't close the book," commented John Hanson, a spokesman for the American Legion, which has 1 million Vietnam veterans among its 3.1 million members.

At issue is a two-decade controversy over several cancers, skin disorders, miscarriages and birth defects that Vietnam veterans blame on the military's use of a herbicide, nicknamed Agent Orange.

Sprayed from planes, helicopters, boats, tanks and even backpacks in

Vietnam from 1965 to 1970, it killed crops and exposed enemy troops hidden in jungles. Named after the orange-striped drums it came in, Agent Orange contained dioxin, a toxic chemical linked with cancer and birth defects in animals that is considered the deadliest of man-made poisons.

Anthony Principi, a deputy VA secretary, said the VA's decision immediately affects between 1,600 and 1,800 Vietnam veterans with non- Hodgkin's lymphoma, a rare cancer that attacks the lymphatic system.

Because the cancer takes 20 to 25 years to surface, the VA expects an additional 450 cases a year, Mr. Principi said.

As of January, the VA had denied disability compensation claims from 36,231 of the Vietnam War's 2.9 million veterans for disorders they believe were caused by Agent Orange exposure, including non-Hodgkin's lymphoma.

To date, the VA has granted just five claims connected to Agent Orange for a severe form of acne called chloracne.