Inflation Rate Soars to 6.1% Gain for 1990 : Economy: Nationwide, it was the steepest rise since 1981. For Southland consumers, the price index rose 6.6%.

Consumer prices nationwide rose a moderate 0.3% in December, pushing inflation for all of 1990 to 6.1%, the worst rate in nine years, the government said today.

Last month’s seasonally adjusted gain in the Labor Department’s consumer price index matched the increase in November but represented a substantial moderation from August through October, when the monthly increase averaged 0.7%.

For the year, the price rise was the steepest since the cost of living soared 8.9% in 1981. It represented a marked increase over the 4.6% rate in 1989 and the 4.4% rate in both 1988 and 1987.

Prices in Southern California rose a smaller 0.2% in December, up from 0.1% the month before. With the exception of apparel and upkeep costs, all major categories of consumer spending registered price gains. For the year, Southland prices were 6.6% higher.

Separately, the Federal Reserve reported today that industrial production fell 0.6% in December, continuing a three-month decline that included a 1.8% plunge in November. For the year, output was off 1.4%.

The Commerce Department, meanwhile, said business inventories grew 0.3% in November while business sales fell 1.2%. Rising inventories of goods held on shelves and backlots are a sign of economic weakness and could foreshadow production cutbacks and layoffs at factories if sales do not pick up.

Analysts expect lower inflation this year because of the sluggish economy. They also expect falling oil prices after the resolution of the Persian Gulf crisis.

Energy prices, which had risen sharply in the three months after Iraq’s Aug. 2 invasion of Kuwait, fell 0.4% in December, after a 0.5% rise in November.

For the year, energy was up 18.1%, the worst since 1979. Gasoline prices were down 0.3% in December, despite a 5-cent-per-gallon federal excise tax that took effect Dec. 1. They were 36.8% higher than a year ago.

Fuel oil prices dropped 3.6% last month but were up 29.9% for the year. Electricity costs, however, rose a modest 1.4% for the year and natural gas was up only 1.8%.

Food and beverage prices rose a scant 0.1% in December, held back by a 1.1% drop in fruit and vegetable costs. That category, however, is expected to rise sharply in January because a freeze in California damaged crops.

For the year, food and beverage costs rose 5.3%, roughly in line with the advances during the previous two years. Pork prices rose 16.7% during the year and beef was up 8.9%. However, egg prices were 4.6% lower than a year ago and dairy products rose only 3.1%, held back by a 1.1% drop in December.

Prices excluding the volatile food and energy sectors were up 5.2% in 1990, compared to 4.6% in 1989 and 4.7% in 1988. The so-called core rate in 1990, considered a better gauge of underlying inflationary pressures in the economy, was the fastest rate since 1981’s 8.5%, but it is expected to be lower this year.