UPDATE 1-Terex reports 1st-qtr loss, cuts outlook

* Reports Q1 loss of 79 cents a share

* Says sales fell 45 percent to $1.3 billion

* Slashes sales forecast for 2009

* Shares off in after-hours electronic trading

CHICAGO, April 21 (Reuters) - Terex Corp (TEX.N), the world's third-largest maker of construction and mining equipment, said on Tuesday that it swung to a quarterly loss as charges associated with the company's restructuring weighed on a business already reeling from the worldwide economic slowdown.

The Westport, Connecticut-based company said its lost $74.9 million, or 79 cents a share, in the first quarter. During the comparable quarter last year, Terex reported a profit of $163.3 million, or $1.59 per share.

Net sales tumbled 45 percent to $1.30 billion. Stripping out currency effects, Terex said sales fell 37 percent.

Analysts, on average, expected the company to report a loss of 10 cents a share on sales of $1.53 billion.

Terex also lowered its outlook for full-year sales, saying it now expects a decline in the range of 40 to 45 percent compared to 2008. Previously, the company had said it expected those sales to decline in the range of 30 to 35 percent.