The Dow Chemical Co. is selling its Polypropylene Licensing and Catalysts business — including a plant in Norco — to W.R. Grace & Co. for $500 million.

Dow said it expects to complete the deal by the end of the year, pending regulatory approvals.

Dow’s Propylene Licensing and Catalysts business, which makes plastic polymers used in products from carpets to auto parts, employs 90 people worldwide. Around 20 of those employees work at the Norco plant. All of the employees are expected to move to W.R. Grace.

The sale includes the plant in Norco, customer contracts, licenses, intellectual property and inventory.

In March, Dow said it planned to sell the business as part of a focus on high-margin, fast-growing segments.

Columbia, Md.-based Grace said the purchase will enhance its existing catalysts business.

Dow’s strategy involves selling nearly $1.5 billion in non-core assets by mid- to late-2014. Dow also said in March that it was actively looking to sell its plastics additives unit.

The sale announced Friday is another clear demonstration that Dow is moving ahead with its strategy, said Andrew N. Liveris, Dow’s chairman and chief executive officer. In the next 12 months, the company plans to sell other assets that don’t fit Dow’s long-term strategy, which includes focusing on electronics, water, packaging and agricultural sciences.

Dow Chemical sold the stabilizers component of its plastics additives division in January. In the same, month it signed a deal to sell its 50 percent ownership stake in Nippon Unicar Co., a joint venture in the Dow electrical and telecommunications unit.

The chemical company has been looking for ways to reduce costs, improve cash flow and get as much as it can from asset sales. In October 2012, it said it would close 20 manufacturing facilities and cut about 2,400 jobs to cope with the sluggish global economy.

Dow Chemical said Friday that it expects to report a gain on the sale of the global polypropylene licensing and catalysts business and that it will use net proceeds partly to help lower debt, fund growth and to pay shareholders.