Freightliner Corp. of Portland, Ore., took the lead in sales of heavy trucks last monthas the recession-stricken industry limped through its slowest January in nine years.

Sales of 1,572 trucks by Freightliner were off 14.5 percent from a year earlier, giving the company 23.3 percent of total sales for the month, according to U.S. retail sales figures from the Motor Vehicle Manufacturers Association.The January loss was milder than those at Freightliner's major competitors, putting the company in front of the pack after a second-place finish in the heavy truck industry last year.

The Freightliner figures fell short of its 24.9 percent year-to-year gain in December as dealers jockeyed for final standings in the 1991 market share race. But the performance still outdistanced the recession-stricken industry, which limped through its slowest January in nine years.

Industry sales were even lower than reported in estimates a few days ago as deliveries of 6,738 units dropped 19.3 percent from a year earlier in the heavy or Class 8 category, defined by gross vehicle weight ratings over 33,000 pounds. January was also the weakest of any monthly period since 1983.

Paccar Inc. of Bellevue, Wash., edged out Navistar International Transportation Corp. by the slimmest of margins for the month as combined sales of Paccar's two sister divisions, Kenworth Truck Co. and Peterbilt Motors Co. of Newark, Calif., totaled 1,446 units, only one more than Navistar.

Sales of 767 heavy trucks by Kirkland, Wash.-based Kenworth were off 26.8 percent from a year before while Peterbilt delivered 679 units in a 19.2 percent decline. Kenworth's share of all January sales was 11.4 percent while Peterbilt captured 10.1 percent, giving Paccar a combined 21.5 percent market share. Total Paccar sales for the month fell 23.4 percent from a year earlier following the company's third-place finish last year.

At Chicago-based Navistar, sales of 1,445 heavy trucks fell 42.3 percent

from a year before following a year-to-year decline of only 1.3 percent in

December as the traditional front-runner made a year-end push to take first place in the 1991 market share race. Navistar's share of industry sales in January was 21.4 percent.

Sales of 871 units last month by Volvo GM Heavy Truck Corp. jumped 38.7 percent from a year before, giving the Greensboro, N.C.-based builder 12.9 percent of the industry total.

Ford Motor Co. sales of 776 heavy trucks last month were also up by 25.2 percent from a year before. The company accounted for 11.5 percent of industry deliveries in January.

January sales of 568 units by Mack Trucks Inc. of Allentown, Pa., fell 25.5 percent from a year before as the company captured 8.4 percent of the monthly market.