Proterra has authorized shares to raise $75 million, a new round of funding that would push the electric bus maker’s valuation past $1 billion, TechCrunch has learned.

The company authorized the sale of 10,857,762 shares at a price of $6.91 in a Series 8 round, according to a securities filing that was obtained by the Prime Unicorn Index, a company that tracks the performance of private U.S. companies, and reviewed by TechCrunch.

If all of the shares are issued, the company’s total valuation would be $1.04 billion, pushing it into “unicorn” territory, according to Prime Unicorn Index.

Efforts to raise capital come as the company explores an IPO, according to a report last month by Reuters that said Proterra had hired underwriters from Deutsche Bank, JPMorgan Chase and Morgan Stanley.

Prior to this August 2 filing, Proterra had raised a total of $551.77 million in funding from investors that include G2VP, Kleiner Perkins Caufield & Byers, Constellation Ventures, Mitsui & Co. as well as BMW i Ventures, Edison Energy, the Federal Transportation Administration, General Motors’s venture arm and Tao Capital Partners.

Proterra produces electric buses for municipal, federal and commercial transit agencies; it has a line of electric buses, hundreds of which have been sold, that can travel 350 miles on a single charge.