A Durham-based real estate investment firm has raised $16 million in equity to purchase property in Chapel Hill, according to the Securities and Exchange Commission.

Dilweg Capital LLC, a commercial real estate investment firm, filed the Form D on Nov. 17. The filing stated it has raised its total offering amount to purchase four Class A office buildings located in Chapel Hill.

The company announced the acquisition of Quadrangle II, III, IV and V, a total 264,410 square feet on 25.82 acres, on Nov. 7.

The buildings, built in 1988 and 1996, were 91 percent leased at the time of sale. Tenants include Rho, Cempra Pharmaceuticals, Intrahealth international and TMW Systems.

Anthony Dilweg, CEO of the Dilweg Cos., said he plans to invest more than $2.5 million to improve the buildings’ operating systems, common areas and tenant amenities to ensure providing the “best in class” office experience for existing and future tenants, according to the news release.

Companies relying on a Reg D exemption do not have to register their offering of securities with the SEC, but they must first file what’s known as a Form D electronically with the SEC after they first sell their securities.