A sharply increasing portion of America's working mothers say their ideal situation would include a part-time job, rather than working full time or staying at home, a new US national survey finds.

The Pew Research Center survey, being released Thursday, found that only 21 percent of working mothers with children under 18 viewed full-time work as the best arrangement, down from 32 percent in 1997.

Sixty percent of the working mothers said a part-time job would be best, up from 48 percent 10 years ago. And 19 percent said not working at all would be ideal - roughly the same as in 1997.

Cary Funk, a Pew researcher on the survey, said the trend reflected women's latest thoughts on the ideal arrangement for their children.

"I don't think it means people are going to give up their jobs," she said. "It's more of an expression of the difficulties of combining responsibilities at work and home."

The survey also found a shift in preferences among stay-at-home mothers.

Only 16 percent of them said their ideal situation would be to work full-time outside the home, down from 24 percent in 1997. Conversely, 48 percent of them now say that not working at all outside the home is the best arrangement, up from 39 percent who felt that way in 1997.

Fathers with children under 18 had a different outlook - 72 percent said the ideal situation for them is a full-time job, 12 percent said they would prefer part-time work and 16 percent said not working at all outside the home would be best.

The survey was conducted by telephone in February and March among a national sample of 2,020 adults.