* Specs increase bearish bets in CFTC data

* Trading volume sinks as spec exit

NEW YORK, July 18 (Reuters) - ICE cotton rose slightly on Friday in another range-bound session as relentless speculative selling dried up and some mills entered the market to pick up bargains after the market's weeks-long rout on concerns about oversupply.

The benchmark December cotton contract on ICE Futures U.S. settled at 67.74 cents per lb, up 0.13 percent from Thursday. Trading was in a narrow range.

Trading volumes plunged to just over 7,600 lots, which traders said reflected the exit of institutional and speculative cash from the market.

Technically, the market remained starkly oversold, with a Relative Strength Index reading of 19. A reading below 30 indicates an oversold market.

Forecasts of a bumper crop based on large planting acreage and favorable weather continue to keep prices under pressure, even after solid export sales data on Thursday.

Even so, the market's ability to hold above the two-year low of 67.10 cents per lb hit a week ago after the bearish monthly U.S. government crop report is a "glimmer of hope" there might be a rebound in the next week or two, said Plexus Cotton traders.

Data showed speculative investors increased their net short position by 4,923 contracts to 5,732 in the week to July 15. (Reporting by Josephine Mason. Editing by Andre Grenon)