The majority of the stock of the privately held company will be owned by Spectrum Equity Investors, with offices in Boston and Menlo Park, Calif., and $4 billion in invested capital.

The Generations Network had revenues of about $150 million last year but does not release its net profits. It employs about 500 people, 450 of them in Utah.

Tim Sullivan, who will remain as CEO and president of The Generations Network, said the company's board felt it was a good time to reap the maximum value for its shareholders.

"The board determined that given the strong performance of the company of the past 18 months and the bright prospects ahead of us, now was the time to consider several options," said Sullivan, who will sit on the company's new board of directors along with Vic Parker and Ben Spero from Spectrum. Parker and Spero, who were traveling Wednesday, were unavailable for comment.

Sorenson Media, a computer hardware and software company in Taylorsville, and EsNet Ltd., a venture capital firm from Provo, are two of the largest investors of The Generations Network.

Sullivan said the company's 900,000 paying subscribers should not notice a difference in the company's operations, virtually the same message he delivered to employees Wednesday morning.

"There are no anticipated changes in the way we run our business and the kinds of investments we're making," he said.

The company expects the sale to close by the end of this year.

Ancestry.com allows users to research and build family trees online and connect with others who are doing the same. The company has 5 billion records accessible on its Web sites. Some services are free but others require a monthly subscription.

Ancestry.com announced on Tuesday that it was offering DNA testing kits that would allow a user to find people who are genetically related.

Sullivan said the company will continue to enhance its sites by adding records and making them easier to use. It also plans to enhance them with different ways for site users to connect with one another.

He said the sale of The Generations Network won't affect the company's relationship with genealogical societies or The Church of Jesus Christ of Latter-day Saints, which also operates a genealogical Web site and family-history research libraries as part of its beliefs.

"There are sometimes in this state and in these towns a sense that the big commercial player and the big religious player don't see eye to eye," Sullivan said. "In fact I try to use every opportunity I can to to make it clear I think we have what I consider to be a great partnership."

tharvey@sltrib.com