* Gets more document requests for immigration audit areas

* Shares unchanged

Chipotle Mexican Grill Inc (CMG.N) fired about 450 workers in Minnesota after an audit by U.S. immigration officials flagged questionable worker eligibility documents, the company said in a regulatory filing on Thursday.

U.S. Immigration and Customs Enforcement (ICE) audited the company's Minnesota restaurants, which led to the dismissals mentioned above. The agency also is auditing employee documents from the fast-growing burrito chain's restaurants in Virginia and Washington, D.C.

We have received additional requests for work authorization documents covering a small number of individual restaurants, the company said in the regulatory filing.

Chipotle spokesman Chris Arnold told Reuters in an email that the additional ICE requests were for restaurants in the areas already subject to document reviews.

In addition to Minnesota restaurants, Arnold said ICE is auditing 60 or so restaurants in the Washington, D.C. and Virginia area.

Shares in Chipotle were unchanged from their close of $265.54 on the New York Stock Exchange. (Reporting by Lisa Baertlein; Editing by Gary Hill)