Officials in China's most populous province say they have applied to Beijing for relief from a 30-year-old law that limits most couples to only one child.

Officials with the Guangdong Population and Family Planning Commission say they are seeking permission to mount a pilot program under which families would be allowed a second child if either of the parents is from a one-child family.

At present, Chinese law permits families to have a second child only if both parents are from one-child homes. Other exceptions exist for ethnic groups and farm families where the first child is a girl.

Heavily industrialized Guangdong is China's most populous province with more than 100 million people. But its leaders are worried about the difficulties of supporting an aging population and the gender imbalances caused by families having abortions when they expect the child will be a girl.