First Data wants to raise as much as $3.2 billion in what will likely be the biggest U.S. initial public offering of 2015.

The New York-based payments processor on Thursday announced the launch of its IPO of 160 million shares, with the offering price expected to be between $18 and $20 per share. The offering could value the company, based on all its outstanding shares, at nearly $18 billion.The stock will trade on the New York Stock Exchange under the symbol “FDC.”

First Data said it intended to use the net proceeds from the offering to redeem all $510 million of its 11.25% senior unsecured notes due 2021, approximately $2 billion of its 12.625% senior unsecured notes due 2021, and to pay applicable premiums and related fees and expenses, as well as for general corporate purposes.

The company has proved to be the biggest equity bet for KKR, the private-equity firm that acquired First Data in 2007 for $29.8 billion, including debt and fees, according to Bloomberg.

“After cycling through a succession of chief executive officers, KKR recruited Frank Bisignano in 2013 from JPMorgan Chase to run First Data,” Bloomberg wrote. “In 2014, KKR led a $3.5 billion equity infusion to cut debt and kick-start acquisitions — chipping in an additional $1.2 billion of its own funds.”

The funding did raise some eyebrows, however, as the money was raised by KKR Capital Markets, a KKR broker-dealer affiliate, and First Data paid KKR Capital Markets a reported $40.6 million for managing the offering.

First Data’s would be the biggest U.S. IPO to date this year, according to data compiled by Bloomberg. The largest IPOs this year by offering size include Tallgrass Energy GP, which raised $1.4 billion; Columbia Pipeline Partners; Univar; Fitbit; and Blue Buffalo Pet Products.

The third quarter was not kind to initial public offerings. The IPO market slowed to 34 deals, down 43% year-over-year, says Renaissance Capital, the IPO index firm. The market was “hurt by the broad market sell-off and specific sector conditions, including a near absence of tech and energy issuance,” Renaissance Capital said. “In addition, a significant number of IPOs were pulled or delayed due to market conditions or acquisitions. For the first time since 2011, average IPO returns were negative (-4%) and more IPOs ended the quarter below their offer price than above it.”