Goldman Sachs BDC IPO priced at $20 per share -market source

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March 17 (Reuters) - The initial public offering of Goldman Sachs BDC Inc has been priced at $20 per share, a market source said on Tuesday, valuing the business development company backed by Goldman Sachs Group Inc at about $707.6 million.

At that price, the IPO would raise about $120 million. The price is at the low end of the expected range of $20-$21 per share.

Goldman Sachs BDC Inc, which is selling all of the 6 million shares in the offering, is the first business development company backed by an investment bank to go public in the United States.

Shares are expected to start trading on Wednesday under the symbol "GSBD" on the New York Stock Exchange.

BofA Merrill Lynch, Goldman Sachs & Co and Morgan Stanley are among the major underwriters for the offering.

Business development companies, which invest in small and medium-sized companies, pay out at least 90 percent of their taxable income as dividends to avoid corporate taxes.

Goldman Sachs Group, whose stake would drop to 16.48 percent from 19.85 percent after the offering, formed the BDC in 2012.

Goldman Sachs BDC, which invests mainly in U.S. middle-market companies, originated more than $1.27 billion in debt and equity investments through Dec. 31.

Managed externally by Goldman Sachs Asset Management LP, the company has 45 investments in 34 portfolio companies with an aggregate fair value of $914 million.

Goldman Sachs BDC's portfolio includes diversified holdings like electronic equipment maker Artesyn Embedded Technologies, aerospace company Heligear Acquisition Co and Extraction Oil & Gas Holdings LLC.

Net proceeds from the offering would be used to repay debt, the BDC said.

Goldman Sachs BDC's net investment income after taxes more than tripled to $52.74 million for the year ended Dec. 31.

(Reporting by Avik Das in Bengaluru; Editing by Leslie Adler)