(Reuters) - Private equity firm TSG-backed Dutch Bros is aiming for a valuation of over $3.3 billion in a U.S. initial public offering, a regulatory filing by the coffee chain showed on Tuesday. Dutch Bros, founded in 1992 by brothers Dane and Travis Boersma in Oregon, plans to raise more than $421.05 million in the IPO. The brothers grew up working at the family’s dairy farm, but due to industry changes were forced to sell their cows and decided to leap into the coffee trend brewing in the Pacific Northwest. They started with 100 pounds of beans, a double-head espresso machine, and a pushcart by the railroad tracks dispensing as many free samples as possible. In 2005, Dane Boersma was diagnosed with Lou Gehrig’s disease and passed away in 2009. The coffee chain opened its first franchise in 2000 and now has 470 drive-thru coffee locations in 11 states with over 16,500 people employed by its franchise partners. In 2018, TSG bought a minority stake in the company for an undisclosed sum. Dutch Bros reported a 13% rise in franchising and other revenue to $47.1 million for the six months ended June 30, compared to a year earlier when it saw a decline in same shop sales related to the COVID-19 pandemic and the west coast wildfires. Dutch Bros will list its stock on the New York Stock Exchange under the symbol “BROS”. BofA Securities, J.P. Morgan and Jefferies are lead underwriters on the offering. Reporting by Sohini Podder in Bengaluru and Noor Zainab Hussain; Editing by Shinjini Ganguli Our Standards: The Thomson Reuters Trust Principles.