NEW DELHI - India's antitrust regulator has imposed penalties on sugar mills for rigging bids in a joint tender floated by state fuel retailers to buy ethanol for blending with petrol, the finance ministry said on Tuesday.

The Competition Commission of India (CCI) has imposed penalties on 18 sugar mills and two associates of Indian Sugar Mills Association and Ethanol Manufacturers Association of India for rigging bids in the tender floated on Jan. 2, 2013, the ministry said on Twitter.

The ministry did not elaborate on the quantum of penalties.

(Reporting by Nidhi Verma, Editing by Sherry Jacob-Phillips) ((nidhi.verma@thomsonreuters.com; +91 11 49548031; Reuters Messaging: nidhi.verma.thomsonreuters.com@reuters.net))