HANGZHOU -- The family planning authorities in east China's Zhejiang Province have loosened their one-child policies to encourage couples to have their second child earlier in the hope of easing the pressures created by an aging society.

Couples eligible to have second babies, including those who are both only children and those from ethnic minority groups, have been required to have their second child at least four years after their first in recent years.

According to the new policy, couples eligible to have a second child can choose when they want to have it, said Zhang Wenbiao, head of Zhejiang Provincial Population and Family Planning Commission.

He said the old policy did not help to tackle the unbalanced age structure of the population in Zhejiang.

"Belated delivery may also be detrimental to the health of women and their babies as more women in urban areas are getting married in their thirties," he added.

Over the next few decades, the province will see a rapid increase in its aging population and a steady decrease in the number of the population of working age, said Zhang.

The commission predicts that during the period of 2006 to 2011, about 177,000 babies are expected to be born earlier in the province, compared with those years when the "birth-interval" policy took effect.

But Zhang said it would not add to the province's gross population. The birth rate will remain around 1.5, within the country's requirement of 1.8, he said.

Zhejiang had more than 6.7 million senior citizens at the end of 2006, accounting for almost 15 percent of its total population. The majority of the working people in the province are aged 40.9 on average, which represents an aging tendency, according to the statistics from the provincial academy of social sciences.