NEW YORK (AP) — West Corp., which provides conference call services and sells software to handle 911 emergency calls, said Thursday that its initial public offering of nearly 21.3 million shares priced at $20 per share, below its expected range.

The company had said it expected to sell the shares from $22 to $25 apiece.

West's shares will start trading on the Nasdaq Global Select Market Friday under the ticker symbol "WSTC." The Omaha, Neb., company said the underwriters of its IPO will have an option to buy another 3.2 million shares to cover extra demand.

The IPO is expected to raise $425.5 million before expenses and underwriting discounts. If all additional shares are sold, that total will rise to $489.3 million. West plans to use most of the proceeds to repay debt.

West was founded in 1986 and was a public company for a decade before investors took it private in 2006. In 2012 West reported a profit of $125.5 million on $2.64 billion in revenue.

Goldman, Sachs & Co. and Morgan Stanley & Co. LLC are acting as lead bookrunners for the offering; BofA Merrill Lynch, Barclays, Citigroup, Deutsche Bank Securities and Wells Fargo Securities are acting as joint bookrunners; Baird and William Blair are acting as co-lead managers; and Evercore Partners and Sanford C. Bernstein are acting as co-managers.