March 15 (Reuters) - Y Combinator's Sam Altman is joining forces with veteran Wall Street dealmaker Michael Klein to launch a blank-check firm that is seeking to raise up to $1 billion, according to a regulatory filing on Monday.

Altman, who will also be designated as the co-founder of AltC Acquisition Corp, continues to be chairman at Silicon Valley startup accelerator Y Combinator, which over the years has influenced the creation of dozens of leading startups including Airbnb and Dropbox Inc.

Altman's blockbuster tie-up with Klein comes as dealmaking through special purpose acquisition companies (SPACs) continues to scale new highs and record volumes of deals are getting signed.

According to data from Dealogic, SPACs have already raised about $79 billion though IPOs this year and are poised to comfortably overtake last year's tally of $82 billion.

A SPAC is a shell company that raises money in an IPO to merge with a privately-held company which then becomes publicly traded as a result. It has emerged as an alternative to a traditional IPO.

Klein left Citigroup in July 2008, weeks ahead of the collapse of Lehman Brothers. He went on to advise Britain's government during the global financial crisis and eventually launched M Klein & Co, a boutique investment firm.

Klein, who has worked as a corporate finance adviser, represented Dow Chemical on its $130-billion merger with DuPont in 2015 and led several other high-profile deals.

He has been one of the biggest names to join Wall Street's recent rush towards SPACs and has raised billions through his other blank-check firms.

Altman, who is also the co-founder and CEO of artificial-intelligence research firm OpenAI, sits on the boards of Reddit and online travel agency Expedia Group. He is also the chairman of Helion Energy Inc and Oklo Inc, which focus on clean energy solutions. (Reporting by Niket Nishant and Noor Zainab Hussain in Bengaluru; Editing by Vinay Dwivedi and Anirban Sen)