NEW YORK — Ethiopia, which has become the No. 2 source country for children adopted by Americans, implemented changes Thursday that could reduce the number of foreign adoptions by up to 90 percent, the State Department said.

U.S. adoption agencies reacted with dismay, and launched a pet

ition drive urging Ethiopia to reconsider. The State Department warned that pending applications to adopt from Ethiopia could encounter “significant delays” of perhaps six months or more.

The new policy, intended to reduce instances of fraud and ease a heavy workload at Ethiopia’s youth ministry, marks a dramatic turnaround for a country that — in the eyes of adoption advocates in the U.S. — had been a rare international bright spot in recent years.

According to State Department figures, 2,513 Ethiopian children were adopted by Americans in the 2010 fiscal year, second only to China as a source country. Ethiopia had been one of the few nations to significantly increase adoptions to the U.S. at a time when overall foreign adoptions by Americans were dropping by 50 percent from the peak of 22,884 in 2004.

Although U.S. adoption advocates had been concerned about adoption fraud in Ethiopia, several of them described the policy change as an overreaction that had caught them by surprise.

The plan “is a tragic, unnecessary and disproportionate reaction to concerns of isolated abuses,” said the Joint Council on International Children’s Services, which represents many U.S. adoption agencies.

The council’s president, Tom DeFilipo, said he remained hopeful that the policy might be reversed or modified so that adoptions could proceed at a substantial level while undergoing greater scrutiny.

According to the State Department, Ethiopia’s new policy calls for its Ministry of Women, Children and Youth Affairs to process no more than five adoption cases per day — about 10 percent of the caseload it had been handling.

Chuck Johnson, CEO of the National Council for Adoption, said Ethiopia has been making “significant progress” in improving its adoption process. He said State Department officials and adoption experts from various countries were trying to persuade Ethiopia to scrap or soften the new policy while seeking further improvements.

“We are encouraged by the advocacy taking place behind the scenes and hopeful that these collective efforts will bring clarity and an immediate adjustment to this unjust and unnecessary ruling,” Johnson said.

The State Department said the U.S. government, other foreign countries and several non-governmental organizations had been offering to assist Ethiopia in further upgrading of its adoption and child-welfare systems.

In all, more than 4,000 Ethiopian children were adopted by foreigners last year, with the U.S. the largest destination but large numbers also going to several Western European countries.

Adoption advocates said the new policy would result in thousands of Ethiopian children languishing for longer periods in institutions struggling to provide adequate services for them. In all, the impoverished African country has an estimated 5 million orphans and homeless children.

Online:

State Dept. advisory: http://adoption.state.gov/news/ethiopia_alert.html