Shanghai's population is approaching 19 million, a source from the municipal population and family planning commission said.

Permanent residents, including migrants who stayed in the city for six months or more, totaled 18.58 million last year, compared with 13.34 million in 1990, according to the source.

The influx of migrants was the key factor cited for the the city's rapid growth. The migrant population totaled 4.99 million last year.

Though centralized habitation might aggravate pressure on aspects ranging from resource environment, infrastructure, social development and management to public services, it has one more positive trait in combating an increasingly aging population, participants to a forum on convergence of population, social development and administration in big cities heard here on Thursday.

The latest statistics show seniors aged 60 and above accounted for 20.8 percent of the city's registered population in 2007, double the national figure and equal that for developed countries.

Experts to the forum suggested Shanghai should favor a shift from simply paying attention to controlling an increase in population to harmonizing the population rise and improved quality, structure and layout of the people.

The city should also make good use of its population rise and attract more skilled people needed for its expansion. These included outstanding talent from overseas and those who would serve the city's ambition to create a center of economy, finance, trade and shipping.

It was also necessary to build and improve a new mechanism featuring interactive management between the city and a source of migrant people so that migrants come to the city or leave in an orderly way, the experts suggested.