Nov 23 (Reuters) - Canadian gold miner Iamgold Corp said on Monday it will temporarily cut 437 jobs at its Westwood mine in Quebec, reducing the site's underground workforce by about 70% as operations remain suspended since a 'seismic event' in October.

While the company has not specified the nature of the seismic activity, it has launched an investigation to find the cause and said on Monday it will provide an update early next year.

The miner had earlier slashed its full-year total attributable production forecast to between 630,000 and 680,000 ounces, 2.5% lower at the midpoint compared with previous forecasts, citing the drop to the suspension of Westwood.

Iamgold was forced to book C$395 million impairment charges to its full-year 2019 earnings due to increased seismic activity at the Westwood mine in the fourth quarter last year.

The Toronto-based company has four operating gold mines on three continents. Westwood, which began production in the first quarter of 2013, is currently Iamgold's only underground mine. (Reporting by Rithika Krishna; Editing by Krishna Chandra Eluri)