UPDATE 1-First Industrial to cut 46 positions, take charges

* To close offices at four locations * Sees pretax restructuring charges of $1.4 mln-$1.6 mln * Sees impairment charge of about $7.0 mln in Q3

Sept 29 (Reuters) - First Industrial Realty Trust Inc (FR.N) said it is eliminating 46 positions and closing four offices, incurring related restructuring charges in the third quarter.

The Chicago-based company said it has started closing offices in Calgary, Irvine, Salt Lake City and Toronto, with assets in those markets to be managed through nearby offices.

The company, expects to incur a pretax restructuring charge of $1.4 million to $1.6 million and a non-cash impairment charge of about $7.0 million in the third quarter related to a property located in the Inland Empire.

The company said it generated about $77.2 million of gross proceeds through asset sales, secured financings, and equity issuances, and used the proceeds along with available cash to retire about $123.7 million of unsecured senior debt during the quarter.

The real-estate investment trust expects to record a gain of about $18.2 million in the third quarter, partly from five secured financing transactions that it closed with multiple lenders.

Shares of the company were down 8 percent at $6.15 in premarket trade. They closed at $6.67 Monday on the New York Stock Exchange. (Reporting by Divya Sharma in Bangalore; Editing by Aradhana Aravindan)