The San Mateo, California-based company had intended to sell 10.1 million shares at a price underwriters hoped to set between $13 and $15. Some investors have questioned whether the solar panel company deserves the roughly $1 billion valuation.

A representative for SolarCity was not immediately available for comment.

The clean technology sector has suffered some recent high-profile flameouts with the bankruptcies of solar company Solyndra and battery maker A123 Systems. SolarCity was promoted as the most promising alternative energy IPO candidate since the debut of Musk's electric car company, Tesla Motors Inc, in 2010.

Musk is SolarCity's chairman and the first cousin of its co-founders, Lyndon and Peter Rive. In a regulatory filing last week, he said he planned to buy $15 million of SolarCity stock in the IPO.

Google Inc and U.S. Bancorp have helped finance some SolarCity projects, but investors said that determining an IPO price was challenging because there are few publicly traded direct competitors with which to compare it.

At the proposed pricing range, SolarCity would have been the second-most valuable U.S.-listed solar company behind First Solar Inc.

SolarCity's venture capital backers include Draper Fisher Jurvetson, DBL Investors, Mayfield Fund, Shea Ventures and Valor Equity Partners.

Underwriters picked for the IPO include Goldman Sachs, Credit Suisse and Bank of America Merrill Lynch.

The company's shares were scheduled to begin trading on the Nasdaq on Wednesday under the ticker "SCTY."

(Reporting By Olivia Oran in New York and Nichola Groom in Los Angeles; Editing by Tim Dobbyn, Bob Burgdorfer and Matt Driskill)

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