NEW YORK — Shareholders for agriculture and chemicals companies DuPont and Dow Chemical -- both with plant operations in Louisiana -- have approved their merger valued at about $62 billion.

They expect the combination to be official by the end of 2016, but regulators still have to approve it.

Within two years, the company plans to split into three separate publicly traded companies. One company will focus on agriculture, one on material science and one will make and sell specialty products.

DuPont and Dow Chemical were each founded in the 19th century. Their research has brought the world products ranging from Ziploc bags and Saran wrap, developed by Dow, to DuPont's Teflon coatings and Nylon and Kevlar fibers.

More recently they have focused on agriculture because of growing global demand for food supplies. That's boosted sales of genetically engineered seeds, fertilizer, herbicides and pesticides. However in the past few years falling crop prices caused trouble for both companies.

Facing pressure from investors, Dow and DuPont made some moves to simplify their businesses. The two sides also have been eliminating staff and closing facilities as they get ready to combine. DuPont is laying off about 10 percent of its staff worldwide, and last month Dow said it will cut 2,500 jobs. They say the merger will reduce their annual spending by $3 billion.

DuPont spun off its performance chemicals business into a separate company called Chemours last year. DuPont also sold its neoprene business in LaPlace to Denka Performance Elastomer LLC.

As for Dow, it struck deals to shed a big chunk of its chlorine operations, including those in Plaquemine, to Olin Corp., and sold its post-harvest specialty chemical business AgroFresh.

Dow’s Louisiana sites include:

LOUISIANA OPERATIONS: It is one of the state’s largest petrochemical facilities, which includes a 1,500-acre manufacturing facility near Plaquemine and brine operations in Grand Bayou, and close to 3,000 employees and contract workers. The Plaquemine site makes more than 50 chemical products. At Grand Bayou, Dow mines underground salt and water to produce a brine used in making chlorine.

ST. CHARLES: A 2,000-acre manufacturing site in Hahnville, with more than 100 Dow employees and 1,500 contract workers. Products made there are used in plastics, insecticides, film and fabrics.

WEEKS ISLAND: The Iberia Parish facility employs 82 Dow and contract workers. Products are used in making specialized windows, laser lenses and other optical elements.

DOW STERLINGTON: The 80-acre site in Ouachita Parish produces more than 40 specialty products. The site employs 275 Dow and contract workers.

AMERCHOL GREENSBURG: The 50-acre site in St. Helena Parish employs 35 people and makes products found in skin and hair care products, detergents, makeup and toiletries.

DuPont’s only property in Louisiana is the LaPlace facility that manufactures materials used to make Kevlar.