Citing a decline in heavy construction due to the slowdown in new housing, Advanced Steel Technology Inc. in Rome Tuesday said it had sent a letter of Worker Adjustment and Retraining Notification to its employees. The letter, sent May 24, is required by federal law in the case of job reductions. Ninety-one employees have been laid off “for the short term,” according to Linda Hales, human resources manager. Ten non-salaried employees will remain. In a statement, the company said it had never had a layoff since it established the Rome plant in 1990. Advanced Steel Technology has 15 plants in seven countries.