NuStar Energy LP said Thursday it has agreed to acquire Citgo Asphalt Refining Co.''s asphalt operations and assets for $450 million plus working capital, which it estimates will be $100 million at closing.

The assets include a 74,000-barrels-per-day asphalt refinery in Paulsboro, N.J., a 30,000-barrels-per-day asphalt refinery in Savannah, Ga., and three asphalt terminals.

NuStar (NYSE:NS), which is based in San Antonio, expects the acquisition to close near the end of the year.