Undated (AP) _ Cotton futures prices leaped to new seasonal highs Tuesday on the New York Cotton Exchange on buying prompted by continued strong overseas demand for U.S. cotton at a time of shrinking supplies.

On other commodity markets, soybean futures fell while grains advanced; oil futures rose sharply; precious metals were mixed; and livestock and meat futures fell.

Cotton futures settled .15 cent to 1.27 cents higher with the contract for delivery in March at 79.19 cents a pound, a new high for March 1990 deliveries.

Cotton prices have been rising lately because of steady consumption, despite the U.S. economic slowdown.

Ernest Simon, cotton specialist with Prudential-Bache Securities Inc., said demand has remained strong from the Far East, which was believed to be the source of new buying Monday night.

Prices opened higher but made their strongest surge in the session's closing minutes, when several speculative funds put in large buy orders, he said.

''Four or five minutes before the close, this market exploded.''

The cotton market also has been supported by a shrinking supply outlook. In last month's crop report, the Agriculture Department projected a U.S. cotton stockpile of 2.5 million bales on July 31, the end of the current marketing year, compared with last year's ending stocks of 3 million bales.

Soybean futures fell sharply on the Chicago Board of Trade on reports of beneficial rain in soybean-growing areas of Brazil and forecasts for more showers there this week.

''It basically reflected the fact that the dry conditions that fostered the eight days of rallying a week and a half ago are over,'' said Mickey Luth, a grains analyst with Shearson Lehman Brothers Inc.

Wheat futures settled 3/4 cent to 2 cents higher with March at $2.59 a bushel; corn was 1/2 cent to 1 1/2 cents higher with March at $2.45 a bushel; oats were 1/2 cent to 3/4 cent higher with March at $1.09 a bushel; soybeans were 4 cents to 6 1/2 cents lower with March at $5.64 1/4 a bushel.

Crude oil prices jumped nearly $1 per barrel on the New York Mercantile Exchange as a new wave of war jitters injected a bit of life into what has been a sluggish futures market.

Light sweet crude oil settled 44 cents to 89 cents higher with March at $21.85 a barrel; heating oil was .83 cent to 2.15 cents higher with February at 70.43 cents a pound; unleaded gasoline was 1.15 cents to 2.72 cents higher with February at 64.85 cents a gallon; natural gas was 1 cent lower to 1.2 cents higher with March at $1.385 per 1,000 cubic feet.

Platinum futures recovered some of Monday's steep losses on the New York Mercantile Exchange on indications of renewed Japanese buying interest and reports of protests in South Africa, the world's biggest platinum producer, over the loosening of apartheid restrictions.

Gold futures edged lower and silver futures rose on New York's Commodity Exchange.

Platinum settled $3.70 to $3.90 higher with April at $387.20 a troy ounce; gold was 20 cents to 70 cents lower with February at $376.40 a troy ounce; silver was 2.5 cents to 2.6 cents higher with March at $3.867 a troy ounce.

Pork futures fell sharply on the Chicago Mercantile Exchange in sympathy with weak cash prices for pork products.

Near-term cattle futures finished slightly lower amid profit-taking after Monday's gains.

Live cattle settled unchanged to .35 cent lower with February at 77.97 cents a pound; feeder cattle were .17 cent lower to .17 cent higher with January at 90.47 cents a pound; live hogs were .10 cent to 1.02 cents lower with February at 53.25 cents a pound; frozen pork bellies were unchanged to 1.6 cents lower with February at 68.70 cents a pound.