Sweetgreen Inc., the trendy salad restaurant chain headquartered in Culver City, announced this week that it had confidentially filed for an initial public offering (IPO) in the United States.

In a statement released on Monday, the company said it has submitted a draft registration statement to the Securities and Exchange Commission for an IPO.

"The number of shares to be offered and the price range for the proposed offering have not yet been determined," the company said. The initial public offering is expected to commence after the SEC completes its review process, subject to market and other conditions.

Sweetgreen, which counts tennis star Naomi Osaka as its youngest investor, was valued at $1.8 billion after a funding round earlier this year, according to media reports. T.Rowe Price, Lone Pine Capital and D1 Capital Partners are among Sweetgreen's other investors.

Sweetgreen was started by Georgetown graduates Jonathan Neman, Nicolas Jammet, and Nathaniel Ru in 2007. The salad chain started with one location on in Washington, D.C. and now operates more than 120 restaurants in the United States, according to its press release.

Its headquarters and test kitchen, called the Treehouse, are located above its shop at the Platform, 8840 Washington Blvd. in Culver City. The company reportedly uses local and organic ingredients and focuses on healthy, quick meals. They make bowls, a variety of salads, soups and fresh drinks.