A Utah-based construction firm with a major presence in Hawaii is set to become part of a company positioned to become the fourth-largest contractor in the nation.

STO Building Group plans to acquire Layton Construction in a deal expected to be completed by the end of the year, according to both companies.

A price was not disclosed.

Layton, headquartered in Sandy, Utah, has led or helped lead Hawaii projects that include a recent addition to Kapiolani Medical Center in Honolulu, the Embassy Suites hotel in Kapolei, the Ae‘o condominium tower at Ward Village and the resort condo complex Koloa Landing on Kauai.

Hawaii is one of eight states where Layton has regional offices. The company, founded in 1953, has about 1,000 employees and will retain its name.

STO was established as Structural Tone in New York in 1971 and has expanded largely by acquiring other construction firms in recent decades. The company has about 2,200 employees in six states, Canada, the United Kingdom and Ireland.