Emerson will acquire SPX Corp.'s 44.5 percent minority interest in EGS Electrical Group, giving it 100 percent ownership of the business. Among the brands in the Rosemont, Ill.-based group are Appleton, Nelson Heat Trace and SolaHD.

Emerson and SPX have jointly held the business since 1997, with Emerson responsible for operational management and consolidation of results in its Industrial Automation segment. The business had annual revenues in 2013 of more than $500 million.

As a global manufacturer of electrical products for industrial, hazardous, adverse and commercial environments, EGS' technologies serve a range of markets. Its oil, gas and chemical participation has grown to more than half of total sales.

The transaction is expected to close within two months, subject to required regulatory approvals, with a purchase price of $571 million.