Washington ? The Bush administration on Monday proposed giving power plants up to 15 years to install new technology aimed solely at reducing mercury pollution, a week after science advisers said the government should be issuing stronger mercury warnings to pregnant women.

The Environmental Protection Agency’s first-ever proposed controls on mercury pollution from power plants would be less than the limits envisioned by the Clinton administration, letting owners in some cases delay meeting requirements until 2018. They would let industry meet the first six years’ goals by using pollution controls already installed to stem smog and acid rain.

“These actions represent the largest air reductions of any kind not specifically mandated by Congress,” said Mike Leavitt, the new EPA administrator. “We are calling for the largest single industry investment in any clean air program in U.S. history.”

EPA also proposed a measure for power plants to cut smog- and soot-forming chemicals from their smokestacks. Together, the programs are estimated to cost $5 billion or more for industry to enact.

But while EPA said it was concerned about mercury, the Food and Drug Administration was told last week by a scientific advisory panel that it should provide clearer advice to pregnant women and young children on the risks from mercury in their diet.

The panel told FDA that it could do a better job of spreading word on which fish have too much mercury, particularly that white, or albacore, tuna has nearly three times as much mercury as cheaper “light” tuna.

Bush’s EPA had been following a Clinton administration plan to require each power plant to use the best technology available to cut mercury emissions and other toxic pollutants by 90 percent within four years.

But the White House and Leavitt now want to allow utilities to rely for the first six years on mercury pollution controls already installed to stem other pollutants that cause smog and acid rain.

That approach, EPA says, would eliminate about 14 tons a year of mercury emissions from the currently unregulated 48 tons a year generated by coal-fired power plants. Such plants account for about 40 percent of the nation’s mercury pollution.

Environmentalists who oppose the Bush plans say the 14 tons reduction would be only about a third of the more ambitious cuts the Clinton administration considered in 2000 that would have required each plant to install the best mercury controls by 2008.

The Clinton administration had listed mercury as a “hazardous air pollutant.” The Bush administration would undo that by placing mercury — which can damage growing brains of fetuses and young children at high enough concentrations — under a less stringent category of the Clean Air Act, so it can be regulated using a program allowing companies to buy pollution credits from other plants.