April 23 (Reuters) - Bill Foley, one of Wall Street’s most prolific investors, has stepped down from his positions in two blank-check firms - Foley Trasimene Acquisition Corp and Austerlitz Acquisition Corp I, their regulatory filings showed on Friday. Foley, who has raised billions so far through special purpose acquisition vehicles (SPAC), quit as chairman of Foley Trasimene, but will continue to advise the firm on its strategic initiatives, including its merger with Alight Solutions. In January, the company had agreed to take Alight, a benefits services provider owned by buyout firm Blackstone Group , public in a deal valued at $7.3 billion. The company said the board has reduced its size to four members and appointed Richard Massey as chairman. Foley will become chairman of the Alight board after the completion of the deal. At Austerlitz Acquisition Corp I, he was a board member. The two resignations were not due to any disagreement on policies or practices, the filings said. (Reporting by Dania Nadeem in Bengaluru; Editing by Arun Koyyur)