Snap, the parent company of messaging app Snapchat, has filed to list on the US stock market, according to several reports.

Based on investments so far, the California-based firm would be worth between $20bn and $25bn (£16bn-£20bn).

That would make it the largest US flotation since Chinese e-commerce giant Alibaba listed two years ago.

Snapchat's parent company Snap declined to comment on the reports to the BBC.

The company began in 2012 as a mobile app that allowed users to send photos that vanish within seconds.

It now has 100 million daily users, which is more than Twitter.

And with 60% of its users aged between 13 and 24, it is seen as an appealing way for advertisers to reach young people.

Snap's founder, 26-year-old Evan Spiegel, turned down an offer from Facebook founder Mark Zuckerberg to buy Snapchat for $3bn just three years ago.

If it goes ahead, it would be the biggest US technology flotation since Facebook's $81bn launch in 2012.

According to several reports, Snapchat has filed a confidential application for an initial public offering with the Securities and Exchange Commission.

The US Jumpstart Our Business Startups Act allows companies with less than $1bn in revenue to secretly file.

The idea is that firms can test the appetite among investors, while keeping their finances confidential.