Credit Suisse First Boston and J.P. Morgan Chase are preparing to bring to market a $250 million loan backing the acquisition of AMI Semiconductor, formerly American Microsystems (AMI), according to officials familiar with the matter. Citicorp Venture Partners and Francisco Partners, both private equity firms, are leading the buyout. The loan is structured as a $75 million revolver and a $175 million term loan "B." Pricing on the revolver is 3% over LIBOR, while the "B" tranche's spread is 31/2 % over LIBOR. Further credit details could not be ascertained. CSFB is administrative agent and Morgan Chase is syndication agent. Company and bank officials did not return phone calls. Officials at Francisco Partners declined to comment. The firms announced a definitive agreement to acquire nearly 80% of the company last December, which was valued just over $525 million. GA-TEK, a Japanese subsidiary of Energy Corp., will retain the remaining 20% and will also be granted a warrant to purchase an additional 10%.