Local governments in the eastern province of Shandong could fail their annual appraisals if they don't curb growing sex ratio imbalances, the provincial government has said.

Shandong, one of China's most populous provinces, has a population of 90 million, with higher-than normal sex ratio, according to a report by the general office of the provincial government released on Sunday.

The sex ratio, which refers to the proportion of males to females, is believed to be normal when 106 boys are born for every 100 girls.

Influenced by the traditional belief that boys could carry forward the family bloodline, many couples, especially in rural areas, show a strong preference for boys.

"In some counties, the sex ratio reaches 110, which means 110 boys are born for 100 girls," said an official with the general office.

To curb the growing sex ratio, the province decided to include the "sex ratio" in the assessment criteria for governments at all levels. In that way, if a government failed to keep the local population or sex ratio within designated limits, it would fail its annual assessment, which would mean that officials would lose awards and chances of promotion.

Shandong's targets are a population of 95.15 million with a sex ratio of 109 by 2009.

Serious gender imbalances in China occurred after the late 1980s when B-ultrasound technologies used for sex-selection became widely available and many Chinese women chose to abort after learning that they were carrying female fetuses.

The current sex ratio for newborns in China is 119 boys to 100 girls, with imbalances of up to 130 in parts of some provinces such as Jiangxi, Guangdong, Anhui and Henan, according to a report late last year from the China Youth and Children Research Center and Beijing's Renmin University of China.