CHICAGO, Sept 7 (Reuters) - Chicago Mercantile Exchange live cattle futures slid to three-month lows on Tuesday, as beef demand slows, leaving cattle producers with ample supply as packer demand softens, traders said.

"Packers are bought for a long ways out - have a lot of inventory," said Scott Varilek, broker at Kooima Kooima Varilek Trading Inc.

CME October live cattle settled up 1.050 cents at 123.750 cents per pound after hitting 123.675 cents, its lowest price since June 9.

October feeder cattle lost 2.425 cents to 160.050 cents per pound reaching their lowest since July 21 at 159.150 cents.

October live cattle is nearing the contract's 200-day moving average, having fallen below its 100-day moving average on Friday.

Beef prices eased, with choice cuts of boxed beef down $1.23 to $335.19 per hundredweight (cwt) while select cuts dropped by $2.23 to $301.90 per cwt, the U.S. Department of Agriculture said.

Margins for beef packers were about $904.75 per head of cattle, down from $923.10 on Friday and $945.95 a week earlier, according to livestock marketing advisory service HedgersEdge.com.

Markets briefly reacted positively to news that Chinese beef importers had suspended exports by top supplier Brazil due to two cases of mad cow disease, though gains were erased after the country said it would still make purchases in anticipation of a quick resumption of trade.

CME lean hog futures ended lower, with the most-active October contract settling down 1.475 cent at 88.100 cents per pound.

The CME Lean Hog Index, a two-day weighted average of cash prices, fell to $100.06 per cwt, its lowest since April 2. (Reporting by Christopher Walljasper; Editing by Shailesh Kuber)