Venture Investors LLC, the largest and oldest Wisconsin-based venture capital company, will announce Sunday it has $80 million in commitments for a fifth venture capital fund.

The Madison firm fell short of the $150 million it set out to raise, but was able to secure more than half of its goal in a challenging venture capital fundraising environment. The new fund is smaller than Venture Investors’ fourth fund, which managed $118 million and was the biggest early-stage investment fund ever raised in the state.

“There have been big changes in the industry and, given this as a backdrop, we’re very happy to have successfully raised a fund,” said John Neis, managing director and head of the company’s health care practice.

Venture Investors Early Stage Fund V L.P. will invest in “untapped opportunities” in the Midwest, with a focus on technologies coming out of the region’s research universities, Neis said.

Western National Mutual Insurance Co., of Edina, Minn., is a new investor in the fund. Investors in the firm’s previous funds that made new commitments include: State of Wisconsin Investment Board; an affiliate of Venture Michigan Fund; Wisconsin Alumni Research Foundation; American Family Insurance; WEA Insurance; Thrivent Financial; and MGE Energy.

The new fund has already made six investments, Neis said. It put money into two Madison companies:Madison Vaccines Inc., a developer of DNA-based therapeutic vaccines for patients with prostate cancer, andNextt Inc., which is building a private social network for friends to connect online.

The other four companies the fund invested in are in Cleveland, Ohio; Detroit; Plano, Texas; and San Clemente, Calif. Including the new investments, Venture Investors has backed a total of 68 companies, Neis said.

The number of Wisconsin companies the new fund invests in will be based on “how the opportunities present themselves,” Neis said. He expects about 80% of the fund will be invested in the Midwest.

Historically, Venture Investors’ portfolio companies have been in the life sciences field. The recent investments represent a tilt toward information technology-based companies, a trend that is playing out around the country.