CHICAGO, March 21 (Reuters) - Chicago Mercantile Exchange cattle futures fell on Monday as traders took positions ahead of a U.S. government report later this week that was expected to show burgeoning supplies.

"There is a little bit of concern about excess supplies and large finishing weights," said Rich Nelson, chief strategist with Allendale Inc.

Hog futures firmed after two losing sessions to end last week pushed the front-month contract to its lowest in nearly two weeks.

CME April lean hog futures gained 1.225 cents to end at 100.625 cents per pound. Most-active June hogs rose 3.75 cents to finish at 119.825 cents per pound, breaking through technical resistance at their 10-day moving average.

CME's most-active June live cattle fell 0.725 cent to 136.35 cents per lb. April feeder cattle dropped 1.125 cents to 161.2 cents per lb, while most-active May feeder cattle dropped 1.7 cents to 165.75 cents per lb.

The U.S. Agriculture Department will release its monthly cattle on feed report on Friday at 2 p.m. CDT (1900 GMT)

Choice cuts of boxed beef rose by $1.26 to $259.42 per cwt by Monday morning, according to the USDA data. Select cuts gained $1.94 to $252.59 per cwt. (Reporting by Mark Weinraub; Editing by Shailesh Kuber)