UPDATE 1-Certicom urges investors to sit tight on RIM bid

TORONTO, Dec 11 (Reuters) - Certicom Corp CIC.TO said on Thursday it believes a C$66 million ($54 million) takeover bid from BlackBerry maker Research In Motion (RIM.TO) undervalues the company, and it urged shareholders to take no action until getting a formal evaluation from its directors' committee.

RIM made an unsolicited C$1.50 a share offer for the encryption software maker early this month after being spurned in its attempt at a friendly deal.

Certicom said it has hired financial and legal advisers to assist the special committee of the board in reviewing the offer and examining other strategic options.

It said it will have a formal response to RIM's bid by Dec. 29. The offer expires Jan. 15.

Certicom shares closed up 3 Canadian cents at C$1.73 on the Toronto Stock Exchange. RIM fell C$1.99 to C$46.59.

($1=$1.23 Canadian) (Reporting by Jeffrey Jones; editing by Rob Wilson)