Symbotic (SYM) said late Wednesday that it is launching an underwritten public offering of 10 million Class A common shares.

The offering includes 6.5 million shares from Symbotic and 3.5 million shares from selling securityholder SVF Sponsor III, an affiliate of SoftBank Group, the company said.

Underwriters have a 30-day option to purchase up to 1.5 million additional shares.

Symbotic added that net proceeds from the offering will be used for general corporate purposes.

Shares of the company were down about 13% in after-hours activity.