Paul Singer, a billionaire hedge fund manager a Republican donor, has contributed to a third political action committee supporting congressional candidate Elise M. Stefanik.
On May 14, Mr. Singer donated $100,000 to New York 2014, a PAC connected with John Faso, a 2006 gubernatorial candidate for New York state.
New York 2014 has spent $366,299 on direct mail and television advertising supporting Ms. Stefanik in the Republican primary election.
Mr. Singer also donated $250,000 to American Crossroads, a GOP super PAC running attack ads against Ms. Stefanik’s opponent, Matthew A. Doheny, and is connected to Winning Women, a PAC that donated $110,000 to Ms. Stefanik’s campaign.
The primary election is Tuesday. Ms. Stefanik has been endorsed by the New York state Conservative Party and Mr. Doheny has been endorsed by the state Independence Party.
Democrat Aaron G. Woolf and Green Party candidate Matthew J. Funiciello are also in the race.