Charleston-based software firm Benefitfocus has revised the terms of it proposed initial public offering, saying its biggest investor plans to cash in as much as $50 million from the sale. Wall Street powerhouse Goldman Sachs & Co., which owns two-thirds of the company, is planning to sell 1.5 million shares and trim its stake to about 51 percent, according to a document filed with the Securities and Exchange Commission last week.

That would raise $34.5 million at the anticipated mid-range sale price of $23 a share. Affiliates of the New York-based bank invested nearly $106 million in Benefitfocus in early 2007.

If the IPO is a hit, Goldman Sachs has the option to sell an additional 675,000 shares, giving it another $15.5 million and cutting its ownership to about 49 percent.

None of that money would go to Benefitfocus. The Daniel Island-based technology company plans to raise about $61 million after expenses by offering 3 million shares in the sale.

Founded in Mount Pleasant about 13 years ago, Benefitfocus develops and sells workplace software products that employees can use to compare, sign up for and manage their benefits, such as medical coverage. Its primary customers include large businesses and health insurers.

A date for the IPO has not been set. The company plans to list its shares on the Nasdaq Stock Market under the symbol BNFT.

"The principal purposes of this offering are to increase our financial flexibility, increase our visibility in the marketplace and create a public market for our common stock," Benefitfocus said in a filing last month with the Securities and Exchange Commission.

Without elaborating, the company said it expects to use the IPO proceeds "for working capital purposes and other general corporate purposes, including executing our growth strategy, developing new products and services, and funding additional capital expenditures, potential acquisitions, and investments."

Benefitfocus hasn't turned a profit in the last three years, with losses totaling about $32 million since 2010, the filing showed. Sales last year jumped 19 percent from 2011 to $81.7 million. Benefitfocus reported a net loss of $15 million on $48 million in revenue for the first half of 2013.

Benefitfocus has 800 employees spread among its local office and its outposts in the Upstate, Oklahoma and San Francisco.