** Shares of Australia's Domino's Pizza Enterprises DOM.AX fall as much as 4.9% to A$21.56, its lowest level since December 10

** Stock currently down 3.3% at A$21.93 after brokerage Citi downgrades the stock to "Sell" from "Neutral"; maintains PT of A$19.85

** Citi cites valuation concerns following recent share price appreciation, with the firm's expected total return turning negative

** Citi flags key growth markets, such as Japan and France, remain challenged, while significant operational improvements still needed at franchise level

** Says uncertainty over senior leadership roles and disruption from cost-cutting initiatives contribute to cautious outlook

** DMP has lost 4.3% so far this week

** Stock touches lowest level since December 10 in its third straight session of losses

** Stock down 25.6% YTD

(Reporting by Roushni Nair in Bengaluru)

((Roushni.nair@thomsonreuters.com))