Lyft on Thursday said it had filed a confidential draft registration statement with regulators to go public.

It's the first major ride-hailing company to officially launch its initial public offering, beating its much larger competitor Uber.

Lyft's offering is widely expected to come in early 2019.

Lyft has officially filed paperwork with the top US stock market regulator to go public, the ride-hailing giant announced Thursday morning.

The confidential draft registration statement, submitted to the Securities and Exchange Commission, is the first step to an initial public offering for Lyft.

It's a big step in what's largely considered to be a race to go public between Lyft and its much larger rival Uber, which is also considering an IPO next year but has been coy about the timing of its float.

Lyft did not elaborate on pricing, number of shares, or targeted valuation. Those specifics will come after the SEC completes its review. The actual offering is likely to come early next year. The company was most recently valued at $15 billion, and a public offering could boost that number.

Read more: Lyft has a 'clear early mover advantage' in beating Uber to an IPO

A Lyft representative did not immediately respond to a request for comment from Business Insider.

The company began lining up banks as recently as October, with Credit Suisse assisting with the deal. Other firms reported to be involved are JPMorgan and Jefferies.

Not content with its roughly 35% market share in the US, Lyft has also been branching beyond traditional ride hailing as it seeks further growth. Last week, its acquisition of Motivate, the country's largest bike-share operator, officially closed. The purchase adds bikes and scooters in most major cities to its arsenal, now known as Lyft Bikes.

Uber, still the world's largest ride-hailing company by far, is also working toward an IPO next year. Its valuation could easily overshadow Lyft's offering, with a reported target of $120 billion. Unlike Lyft, Uber has self-reported quarterly financials. Most recently, those numbers showed slowing growth and widening losses for the company.

Lyft, which is also not profitable, brought in $563 million in revenue during the third quarter — up from $300 million in the same period a year ago — but with losses increasing to $254 million from $195 million. The company expects to have full-year revenue of $10 billion to $11 billion, sources told Bloomberg.

Despite the differences, so-called "first mover advantage" could be huge for Lyft, one analyst told Business Insider, adding that the company's economics seem to be in better shape than those of Uber's.

IPO valuations can change drastically in the lead-up to a public offering. Snap, for example, was thought to be valued as high as $40 billion ahead of its IPO in 2017, but that number eventually fell by about half, to $20 billion.