SACRAMENTO -- California's home-building slump deepened in August to a seven-year low, as requests for residential building permits dropped 4.6 percent in one month, a statewide builders group said this week.

During the first eight months of the year, home builders received permits for 127,370 units, down more than 21 percent from the 161,628 permits drawn during the same period last year.

The slide prompted industry analysts to cut their housing production estimates for 1990 and 1991. The Construction Industry Research Board now projects 176,000 housing units will be built in California this year and 168,000 units will be constructed next year. The group initially estimated more than 200,000 new housing units would be built both years.

The downturn in construction is centered in Los Angeles and Riverside counties, which account for nearly half of the statewide decline in building permit requests this year, said Robert Rivinius, executive officer of the California Building Industry Association.

Rivinius blamed the home-building slump on higher interest rates, the crisis in the Middle East, consumer fears of a recession and a stubbornly sluggish market for used homes.

"The Mideast situation must be solved, along with a decline in interest rates, to allow the economy to grow and stimulate increased sales and purchases in the overall marketplace," Rivinius said.

"Many builders are reevaluating and redesigning their product line in an effort to make housing affordable to more of the home-buying public," he said.

Residential building permits issued in August indicated an annual rate of 144,900 -- the lowest annual rate for any month since the March 1983 total of 106,400 housing units. Activity in August included permits issued for 91,400 single-family units and 53,500 multifamily units.

The August annual rate total was 32.6 percent below the August 1989 mark of 214,900 housing units and 4.6 percent under the July total of 151,900.

Some areas of the state are experiencing increased production activity this year. The Yuba City area posted a 133 percent jump in the number of building permits pulled during the first eight months of the year; Bakersfield, 29 percent; Redding, 59 percent; the Visalia-Tulare-Porterville area, 9 percent; Sacramento, 6 percent; and the Santa Barbara-Santa Maria-Lompoc area, 5 percent.