A prominent Dow Chemical shareholder this week pushed for changes to the chemical giant's plans following its pending merger with DuPont.

The deal to combine the two chemical companies remains under review by antitrust regulators, but executives hope to finalize the merger later this year. Within two years of the deal closing, the combined operation aims to split into three separate, publicly traded companies.

A materials science company will remain in Dow's home of Midland, Mich., while new companies focused on specialty products and the agriculture market will be based in DuPont's native Delaware.

Activist investor Daniel Loeb, however, criticized some aspects of that reorganization this week, and his investment firm, Third Point, unveiled an alternative plan on Wednesday.

The current plan to break up the newly formed Dow/DuPont

Third Point's proposal, according to Chemical & Engineering News, would shift the former Dow Corning silicones business and DuPont’s engineering plastics to specialty products instead of materials science.

Dow's consumer care, energy and water divisions would also go to specialty products, but DuPont’s Tyvek fabric and Dow’s food ingredients business would move from specialty products to materials science.

Third Point argued that under its plan, the specialty products company, in particular, would be able to focus on four specific markets and generate strong shareholder value. The firm estimated that specialty products would trade at a higher price relative to earnings, which could be worth $20 billion to investors.

Dow and DuPont officials, CE&N added, plan to "conduct a comprehensive review" of the proposed split and would "continually solicit and welcome input from our shareholders.”