Photo messaging app Snapchat is preparing for a new round of funding, seeking as much as $500m (£324m) worth of investment in a move that would place the company's valuation at $19bn.

The company rejected an acquisition offer of $3bn from Facebook in late 2013 for being too low, and in July of 2014 a round of investment placed the company's value at $10bn.

According to Bloomberg, executives at the company are in advanced talks with fund managers, and the investments being discussed would place the firm's value somewhere between $16bn and $19bn.

The massive growth in Snapchat's valuation has been driven by its access to the much-sought-after teen demographic, who represent the main users of its self-destructing photo message service. It has only recently begun to monetise the app with ads, but is already reportedly demanding $750,000 a day for campaigns.

While $19bn would represent a huge increase in the firm's valuation, it would only be the third most valuable tech startup that is not currently publicly traded. Chinese smartphone maker Xiaomi, which has rapidly become one of Asia's dominant manufacturers, is currently valued at around $46bn, while ride-hailing app Uber is currently worth approximately $41bn.