(Adds transaction details, background on Origin) Feb 17 (Reuters) - Carbon-negative products maker Origin Materials said on Wednesday it has agreed to go public through a merger with blank-check firm Artius Acquisition Inc, in a deal that values the equity of the combined entity at $1.8 billion. The deal will provide Origin with gross proceeds of $925 million, including a private investment of $200 million from Danone SA, Nestlé SA, PepsiCo Inc and affiliates of Apollo Global Management among others. Sacramento, California-based Origin helps turn carbon found in biomass into useful products, its website showed, capturing carbon in the process. The company formed an alliance with Nestle and Danone in 2016 to produce and commercialize plant-based PET plastic, which has a low carbon footprint. PepsiCo joined two years later. Artius is a special purpose acquisition company (SPAC) - a shell company that raises funds to acquire a private company - raised $630 million through an initial public offering in July. SPACs emerged as Wall Street’s most favored investment vehicle last year and their popularity shows no signs of fading in 2021. By the end of last week,144 SPACs had raised $45.7 billion, according to data from SPAC Research. Origin will be listed on the Nasdaq after the merger and will trade under the new ticker symbol “ORGN”. BofA Securities is the exclusive financial advisor to Origin. (Reporting by Sohini Podder in Bengaluru; Editing by Shounak Dasgupta and Sriraj Kalluvila)