(New throughout, adds background, details and comments from Halliburton) Sept 22 (Reuters) - Halliburton Co will pay $18.3 million to more than 1,000 oil and gas workers it improperly exempted from overtime pay, the U.S. Department of Labor said on Tuesday, the latest development in a nationwide probe into wage practices in the industry. The department said Halliburton improperly identified workers in 28 job categories as exempt from overtime pay under the Fair Labor Standards Act, the U.S. law governing wages and working hours. The company said it had begun paying the overtime and was cooperating with the Labor Department. The settlement is one of the largest for the Labor Department in recent years in an overtime case. Under the law, employees are entitled to... More