This report presents a cost analysis of Linear Low Density Polyethylene (LLDPE) production from polymer grade (PG) ethylene and 1-butene using a gas phase process. The process examined is similar to Univation UNIPOL and INEOS Innovene G processes. This report examines one-time costs associated with the construction of a United States-based plant and the continuing costs associated with the daily operation of such a plant. More specifically, it discusses: * Capital Investment, broken down by: - Total fixed capital required, divided in production unit (ISBL); infrastructure (OSBL) and contingency - Alternative perspective on the total fixed capital, divided in direct costs, indirect costs and contingency - Working capital and costs incurred during industrial plant commissioning and start-up * Production cost, broken down by: - Manufacturing variable costs (raw materials, utilities) - Manufacturing fixed costs (maintenance costs, operating charges, plant overhead, local taxes and insurance) - Depreciation and corporate overhead costs * Raw materials consumption, products generation and labor requirements * Process block flow diagram and description of industrial site installations (production unit and infrastructure) This report was developed based essentially on the following reference(s): (1) US Patent 8957167, issued to Univation in 2015; (2) US Patent 20030171512, issued to Univation in 2003 Keywords: Ethene, PE, Gas Reactor, Copolymer