Call it hibernating capital.

A growing effort to convince wealthy individuals to invest directly in local startup companies is the objective of some leaders in Ann Arbor’s entrepreneurial community.

Michigan has 157,642 households with liquid assets worth at least $1 million, according to Phoenix Affluent Marketing Service. That means Michigan has the 10th most millionaires in the country - ahead of Massachusetts, Maryland, Arizona, Georgia, North Carolina and 35 other states.

Efforts to reinvigorate a 6-year-old group called the Ann Arbor Angels is a direct response to financial need among the area’s startup technology companies, officials said.

The investment group came together for the first time in 2004 but essentially fizzled out after a few years.

But Michael Cole, vice president of the Bank of Ann Arbor’s technology industry group, has mobilized to restart the group and plans to hold 3 to 4 meetings in 2010. The goal is to attract wealthy private citizens to invest in small local tech companies, generating profits, jobs and economic activity for the Ann Arbor region.

Angel investment is an early form of venture capital. The term generally refers to investors who are willing to take enormous risk on an early-stage company before traditional financing options become available.

In return, the angel investors typically get an ownership stake in the company - and it can pay off years down the road if the company enjoys success.

For tech companies, the money is heavenly sent.

“In Ann Arbor we do actually have a decent population of potential investors,” Cole said. “We’re trying to bring this capital off the sidelines.”

LeAnn Auer, executive director of the Ann Arbor-based Michigan Venture Capital Association, said angel investment is important for fostering growth in an entrepreneurial economy. She said it’s distinct from traditional venture capital, where investors have a fiduciary responsibility to earn a return for their institutional investors, such as state pension plans and endowment funds.

“Angel investors, because it’s just typically wealthy individuals, have a lot more leeway in their risk appetite and their things they would invest in and how much,” Auer said. “Angel investment can really fill a need.”

Cole said the Ann Arbor Angels group recently conducted a meeting, which drew 20 people, including about a dozen investors. He said the group plans to conduct another three to four meetings in 2010. The invitation-only meetings are designed to gather angel investors together to listen to business presentations from entrepreneurs seeking investment.

“The purpose is to connect these early-stage companies with potential investors,” Cole said. “It’s a tough, inefficient market for these companies trying to find investors.”

Angel investment is hard to track, but it’s played a key role in boosting several local companies. Medical devices startup Accuri Cytometers, measurement technology firm Coherix and life sciences firm NanoBio, for example, all benefited from early angel investment.

“There’s probably more angel investors who would come out of the woodwork if they only knew what it was all about,” Auer said. “It is vastly important to the region and to Michigan and to their communities. Angel investors typically invest within a 50-mile radius. It can really help find and seed the companies in the local communities.”

Contact AnnArbor.com’s Nathan Bomey at (734) 623-2587 or nathanbomey@annarbor.com. You can also follow him on Twitter.