Infinity Property and Casualty, the US auto insurer, has lowered the price range on its struggling initial public offering (IPO) for the third time in an attempt to complete the deal on Tuesday.

Credit Suisse First Boston (CSFB) and Merrill Lynch, Infinity's underwriters are to offer investors the shares at a new price range of $16 (€15) to $17, sources close to the deal said. Infinity and its underwriters plan to price the deal late on Tuesday.