New orders for factory goods, steadily climbing since November, finally topped the $160 billion level in January for the first time in 16 months, the government said yesterday.

The 2.4 percent seasonally adjusted increase from December to $160.1 billion in January was led by automobile orders, but was widely spread among a wide variety of "big ticket" durable goods, the Commerce Department said.

Growth in orders for autos, steel, non-electrical and construction equipment helped wipe out declines among the non-durable goods, another in the growing number of favorable economic statistics.

Commerce Department chief economist Robert Ortner said figures in many January reports appeared to have been pushed upward by unusually favorable weather. "February and March may tone down the increases," he said.

Still, Ortner said, "I'm very confident the recession ended in December."

The report on orders measured another 1 percent decline in the nation's inventories of unsold goods, showing that factory managers had still not eliminated the overhanging surplus that prevents increases in production and the return of laid off workers.

While the inventory slashing was not ended in January, analysts hope it is no longer the major negative factor that once blocked an economic rebound that most agree is now taking place.

Supporting that view was the shrinkage in the closely watched ratio of shipments to inventories, which in January showed 1.68 months' worth of unsold goods on hand, a substantial improvement from December's 1.74 months.

The inventory cutbacks have been virtually uninterrupted since November 1981. Ortner said such inventory liquidation could continue a few months longer.

The last time new orders were above $160 billion was in September 1981 at $167.7 billion.