UPDATE 1-ELX lashes back at CME, asks CFTC to take action

* Feud grows over transferring positions between exchanges

* Upstart says CME Group's statements 'misleading'

CHICAGO Jan 27 (Reuters) - Upstart exchange operator ELX Futures LP on Wednesday asked its regulator to force bigger rival CME Group Inc (CME.O) to retract "misleading" statements about the status of a rule that would let traders easily transfer positions from CME to ELX.

The Commodity Futures Trading Commission, which regulates futures markets, rejected CME's decision to bar traders from moving their Treasury futures to ELX using a block-trade mechanism, in a Jan. 22 letter made public yesterday.

CME then issued its own statement on Tuesday, saying it was not required to allow such trades, called exchange of futures for futures (EFF), to go through.

"I find it especially disheartening to see the CME putting vague words into the mouth of the CFTC, which could reasonably cause the market to continue to be chilled in its use of EFF," ELX CEO Neal Wolkoff said in on Wednesday to the CFTC.

"I ask that CME be required to post a corrective release to remove these misleading statements."

(Reporting by Ann Saphir; Editing by Andrew Hay)