FRESNO — San Joaquin Valley air regulators said they would miss a federal deadline to clean up the region’s smog and requested an additional 11 years and more than $3 billion to meet federal standards.

The San Joaquin Valley Air Pollution Control District’s draft cleanup plan proposes the lengthy extension to avoid facing federal sanctions that could cut off more than $2 billion in federal transportation funds to the eight county region, air district officials said.

The valley, stretching 240 miles from Stockton to Bakersfield, remains one of the dirtiest air basins in the nation for emissions that create ozone, the main ingredient of smog.

“Even if money were no object we could not achieve these reductions on time,” said Seyed Sadredin, the air district’s executive director. “The technology does not exist today to get us all the reductions we need.”

The 2007 Ozone Plan estimates the district must remove 75 percent of the valley’s smog-forming pollution to attain federal ozone standards. For example, nitrogen oxides emissions need to drop from the current 690 tons per day to just 160 tons per day.

District officials said the extra $3 billion they planned to request would help offer companies incentives to use new, cleaner-running vehicles. Automobiles are blamed for 80 percent of smog-forming pollutants.

Smog, which is created when pollutants from tailpipes, smokestacks and livestock waste react with summer heat, is blamed for causing asthma and makes it harder for people with respiratory conditions to breathe.

Clean air activists said they were disappointed with the plan, which proposes downgrading the San Joaquin Valley to the U.S. Environmental Protection Agency’s worst-offender category for smog. Being classified as a region in “extreme nonattainment” with federal air standards for ozone concentrations would extend the area’s cleanup deadline from 2012 to 2023, officials said.

“I’m very worried about people living with asthma,” said Liza Bolanos, coordinator of the Fresno-based Central Valley Air Quality Coalition. “People will have to suffer longer.”

The district will hold a public workshop on the draft plan before seeking approval from the district board and the California Air Resources Board. It is scheduled to be presented to the EPA by June 15.