U.S. Economy Up Only 1.1% Last Quarter : Business: The GNP’s October-December advance was slimmest in three years.

The U.S. economy posted a 1.1% gain from October through December, the slimmest quarterly advance in three years, helping slow the increase of goods and services to just 3% in 1989, the government said today.

The Commerce Department’s final revision of its fourth-quarter gross national product was up slightly from the 0.9% gain in its estimate last month. The department’s initial estimate in January was 0.5%.

While the improvement was modest, it was further evidence the economy can avoid an immediate recession and continue the longest peacetime expansion in U.S. history.

The growth in the final three months of 1989 followed increases of 3.7% in the first quarter, 2.5% in the second and 3% in the third.

The 3% gain for all of 1989 was the smallest since a 2.7% advance in 1986 and followed increases of 4.4% in 1988 and 3.7% in 1987.

A consensus of economists had predicted that fourth-quarter growth would remain at 0.9%.

Many analysts, however, believe that while the pace of economic growth rose further during the current quarter, partly because of weather-related factors, it will not bounce back in 1990 to the levels experienced during much of the 1980s.

In fact, the latest consensus of top economists projects a 1.7% growth forecast for this year. That would be the poorest performance since economic activity declined 2.5% in 1982 during the last recession.

The fourth quarter’s 1.1% gain was the lowest since a 0.8% advance in the third quarter of 1986.

An inflation index tied to the GNP rose at an annual rate of 4.5% last year, the Commerce Department said, the same as its estimate last month.

The various changes left the GNP expanding in the fourth quarter at a seasonally adjusted annual rate of $4.17 trillion.

The department attributed the final revision to an increase in final sales, which offset a decrease in the amount of inventories.

The biggest drag on the economy in the fourth quarter was durable goods, which declined 14%.

Other areas of weakness included capital spending and housing construction.

Exports, on the other hand, jumped 9.4% in the fourth quarter, while imports rose just 2.2%.

In a companion report, the department said after-tax profits of U.S. corporations rose 2.8% in the fourth quarter.

Corporate profits fell during each of the other quarters of 1989--1.1% in the first, 7.2% in the second and 5.4% in the third.