SEOUL, Jan 7 (Reuters) - South Korea"s Lotte Chemical Corp (011170.KS) said on Friday it plans to build a large-scale petrochemical complex in Indonesia worth $3.9 billion in investment. The project"s commercial production target is 2025, and is aiming to generate annual revenue of about $2.06 billion, the company said in a statement. The complex, which will also involve its subsidiary Lotte Chemical Titan (LOTT.KL), will be located in Banten province, and plans to annually produce 1 million tonnes of ethylene, 520,000 tonnes of propylene, 250,000 tons of polypropylene, as well as downstream products, Lotte Chemical said. Lotte Chemical has signed a memorandum of understanding with Indonesian authorities, and entered into agreement with builders Lotte Engineering & Construction and Hyundai Engineering for the construction, it added. ($1 = 1,202.3800 won)