Scottish craft beer maker BrewDog has been valued at £1bn after nearly a quarter of the company was sold to a US firm.

Founders James Watt and Martin Dickie could reportedly earn up to £100m from the £213m deal with TSG Consumer Partners.

The remaining funds will be used to support the Ellon-based brand's global expansion.

The sale is a departure for BrewDog, which has traditionally relied on its army of shareholders to fund new projects.

Early investors in BrewDog's Equity for Punks programme will be able to cash in some of their holdings.

Shares bought during the first phase in 2010 are now reportedly worth 2765% of their original value, with those purchased in 2016 rising by around 177%.

Mr Watt said: "We are growing mega-fast at the moment. We have broken the record for most consecutive years on the Sunday Times Fast Track 100 and in 2017 we are forecasting our growth will be even faster.

"We recently shared our ambitious five-year plan with our Equity Punk shareholders, which included adding more capacity in Ellon and Columbus as well as building new breweries in Asia and Australia.

"All of these projects are immediate opportunities and they all link completely back into our core mission of making other people as passionate about great craft beer as we are.

"This deal will enable us to take our business, and our community's investment in BrewDog, to the next level."

San Francisco-based TSG Consumer Partners was founded in 1987 and has invested in brands such as vitaminwater and thinkThin.

Managing director Blythe Jack said: "BrewDog is an ideal fit for TSG's mission, which is to partner with visionary founders building next-generation consumer brands."

BrewDog recently revealed plans to build a hotel in the US after plans for a similar development in Aberdeenshire stalled.