China, the largest source of overseas children adopted in the US, plans to bar would-be parents who are obese, single or over 50, according to notices posted on the Web sites of three leading US adoption agencies.

Under rules effective from May 1, applicants must be married for more than two years with at least a high school education. The measures also ban multiple divorcees, the blind and those taking depression medication from becoming parents, according to the postings.

The changes come as the government wants to ensure Chinese children get the best possible homes while demand for the children outstrips the number available for overseas adoption.

The government "is doing what they see as the best thing for their children and their country," said Kristine Altwies Nicholson, who runs Hawaii International Child, a Honolulu-based adoption agency.

The rules were described on the Web sites of Spring, Texas-based Harrah's Adoption International Mission, which has placed 1,200 orphans from Asia since 1995; New Beginnings Family & Children's Services Inc. in Mineola, New York; and Evansville, Indiana-based Families Thru International Adoption. Nicholson said she had heard the same information from people who had met Chinese authorities.

The postings said the China Center of Adoption Affairs briefed overseas agencies on the new rules at a Dec. 8 meeting, without specifying where it was held. The center, part of the Beijing-based Ministry of Civil Affairs, hasn't made the changes public. A man who answered the telephone at the center declined to comment or to give his name.

'Model Program'

"The Chinese government's adoption program is considered a model program in terms of efficiency," Susan Soon-keum Cox, vice president of public policy and external affairs at Holt International Children's Services, testified in June to a subcommittee of the US Senate Committee on Foreign Relations in Washington. Eugene, Oregon-based Holt has placed almost 40,000 children in the US since the 1950s.

China placed 13,000 children with overseas families last year, ministry statistics show. In 2001, the ministry received just 8,000 applications for international adoptions.

A total of 62,000 children entered Chinese welfare institutions such as orphanages last year, down from 66,000 in 2004, according to the ministry. Only certain orphanages can arrange international adoptions.

Guatemala Second

China, the world's most populous nation, has been the leading source of overseas adoptions in the US since 2000. It provided 6,493 children in the 12 months ended Sept. 30, 57 percent more than second-placed Guatemala, visa statistics from the US Department of State show.

US families adopted about half of all Chinese babies available in fiscal 2005, according to US figures and Chinese totals. China does not make public the destinations of adoptees.

Overseas applications last year doubled from 2004, and adoption affairs center officials said they don't have enough children to meet the increase, according to Harrah's Web site.

"It's a supply-demand issue," said Jane Liedtke, chief executive officer in Beijing of Our Chinese Daughters Foundation, which works with 10 US adoption agencies.

China's main rule changes disqualify single parents, anyone divorced more than twice, people aged over 50 and families with net assets of less than US$80,000. Couples must have been married for at least two years.

For couples adopting a child with special needs, the age limit remains 55.

Depression, Anxiety

Also excluded are people with a body mass index more than 40 -- translating to about 5 feet 7 inches (170 centimeters) tall and weighing about 262 pounds (119 kilograms) -- the blind or severely nearsighted and those who have taken depression or anxiety medication in the past two years, the Web sites said.

Previously, rules stated that parents had to be aged over 30. Priority went to those 30 to 45 for children about 1 year old, and applicants 50 to 55 for children above 3 years old.

Health qualifications weren't specifically defined, and there were no education or marriage requirements. The government limited applications by single parents to 8 percent of the total, said Nicholson in Hawaii and Liedtke in Beijing.

About 30 percent of Chinese children went to single parents in 2001, before the quota system went into effect, according to Families with Children from China, a New-York-based support organization.