Undated (AP) _ Cocoa futures prices fell Thursday as the International Cocoa Organization apparently was unable to resolve member differences on rules for price support intervention.

Cocoa lost $38 a ton on the March contract at the Coffee, Sugar and Cocoa Exchange in New York.

In some other markets, soybean and grain futures were mostly lower while livetock and meat were mostly higher.

A dispute among consuming and producing nations over the rules governing the operation of cocoa buffer stocks resulted in an apparent impass at the ICO meeting in London, said Debra Tropp, an analyst in New York with Prudential- Bache Securities Inc.

''They'll be meeting again Jan. 19,'' she said, but the inability to reach agreement this week ''created speculation that implementing the buffer stock might be more problematic than expected.''

The impass arises from the inability to agree to the rules that would determine at what price the buffer stock manager would buy cocoa beans as a price-support maneuver.

The buffer operations were to begin Feb. 1, but this looks doubtful, said Ms. Tropp.

Cocoa futures settled $33 to $38 lower with the contract for delivery in March at $1,859 a ton.

Pork futures moved higher in active trading at the Chicago Mercantile Exchange.

Hog and belly prices started out weaker, setting new lows for the move, but then came back to close higher.

''There was a shift in psychology concerning wholesale pork,'' said Philip Stanley, an analyst in Chicago with Thomson McKinnon Securities Inc.

''Previously, the market was bearish, but now wholesale items are cleaned up so packers can start buying again,'' he said. ''Also, there was talk that cash hogs would be steady to a little higher (on Friday).''

Cattle prices also moved higher, mostly because of technical market support in light trading.

Live cattle settled .05 cent to .42 cent higher with the December contract at 61.42 cents a pound; feeder cattle were .15 cent lower to .22 cent higher with January at 62.62 cents a pound; live hogs were .17 cent to .68 cent higher with December at 55.47 cents a pound; and frozen pork bellies were .15 cent lower to 1.30 cents higher with February at 71.80 cents a pound.

Most grain and soybean futures prices declined on the Chicago Board of Trade, with wheat and corn losing as much as a nickel a bushel. Soybeans were down almost 5 cents.

Traders said the December corn contract triggered sell stops when it fell below $1.65 a bushel. Corn was weaker from the start, pressured by follow- through selling from Wednesday.

The soybean complex was undercut by the stronger dollar and by increased meal deliveries against the expiring December contract, said Mickey Luth, an analyst with Shearson Lehman Brothers.

Wheat settled 5 1/4 cents lower to 1/2 cent higher with December at $2.83 1/2 a bushel; corn was 5 1/2 cents lower to 1/4 cent higher with December at $1.61 1/4 a bushel; oats were 2 cents to 3 1/2 cents lower with December at $1.56 a bushel; and soybeans were 2 cents to 4 1/2 cents lower with January at $4.97 1/4 a bushel.

Energy futures were mostly higher in light trading on the New York Mercantile Exchange.

West Texas Intermediate crude oil slumped below $15 a barrel, but at that point attracted good trade buying, said Peter Beutel, an analyst in New York with Elders Futures Inc.

Crude oil settled unchanged to 8 cents higher with the January contract at $15.20 a barrel; heating oil was .10 cent lower to .16 cent higher with January at 43.94 cents a gallon; and unleaded gasoline was .02 cent to .12 cent higher with January at 41.33 cents a gallon.

Precious metals futures were lower at the Commoditiy Exchange in New York.

Gold settled $3.80 to $4.10 lower with the December contract at $388.40 a troy ounce; and silver was 2.9 cents to 3.9 cents lower with December at 536.1 cents a troy ounce.