NEW YORK (The Deal) -- National Australia Bank Ltd. said Friday, August 29 that it plans to exit Great Western Bancorp. Inc. completely, a day after filing to hold an IPO of the South Dakota-based bank on the New York Stock Exchange that could value it at more than $2 billion.

National Australia, the country's No. 4 bank by value, will sell a minority stake in the IPO and said it would move to offload its remaining stake as soon as possible.

"It is customary in the U.S. to sell a minority stake initially if exiting a business via the public markets," the lender said. "The timing of subsequent sales of GWB [Great Western Bank] shares is unknown and is subject to customary sale restrictions in the U.S., including an initial 180-day lock-up period."

The IPO is the first significant move by CEO Andrew Thorburn since he took control at the start of this month and announced he will refocus the bank on its Australian and New Zealand operations.

Sioux Falls, S.D.-based Great Western had a book value of $1.43 billion according to the IPO registration statement, which was filed with the Securities and Exchange Commission on Thursday, Aug. 28. The unit is likely to be valued at 1.4 times to 2.2 times book value, according to Macquarie Group Ltd. analysts, putting its likely value at between $2 billion and $3.1 billion.

National Australia Bank bought Great Western in late 2007 for $798 million, when it paid 3.4 times book value for the business. The bank was acquired to provide a springboard to accelerate growth in agribusiness banking. It was subsequently merged with National Australia Bank's U.S. commercial banking unit and later acquired assets from TierOne Corp., First Community Bank and North Central Bancshares Inc.

Great Western operates 162 branches in seven states: South Dakota, Iowa, Nebraska, Colorado, Arizona, Kansas and Missouri. The unit reported net income of $77 million for the nine months ended June 30, according to its IPO document.

"We have been clear that our strategic direction is to concentrate on building a stronger core Australian and New Zealand business," Thorburn said in a statement. "The IPO of the U.S.-based Great Western Bank provides us with the opportunity to further focus our attention on our core business."

The Australian bank is also retreating from operations in the U.K. In July, it agreed to sell 625 million pounds ($1.06 billion) of non-performing U.K. real estate loans to an affiliate of New York private equity shop Cerberus Capital Management LP. National Australia Bank had explored a sale of its struggling U.K. subsidiary Clydesdale Bank plc, but ruled out selling the unit in 2012 after a review concluded that the business would have to be sold at a discount to book value. Thorburn made no comment on his plans for the U.K. business on Friday.

NAB has appointed Deutsche Bank AG and Bank of America Merrill Lynch as joint book runners and underwriters for the Great Western sale. The IPO, which will include a capital increase of about $100 million, is expected to get underway before the end of 2014.

The IPO may coincide with the listing of the larger Citizens Financial Group Inc. in New York by Royal Bank of Scotland Group plc. The Edinburgh lender said in May it wants to sell a 20% to 25% stake in the Providence, R.I. business by year-end. Estimates suggest Citizens could be worth $15 billion.

Shares in National Australia Bank closed on Friday at A$35.20, up A$0.43, or just over 1%, on their Thursday close. The bank has a market capitalization of A$83 billion ($77.5 billion).