* Artio selling 23.4 mln shares, sees price at $24-26 each
* Baer could raise $504-546 mln, valuing Artio at $1.5 bln
* Offer to be priced, completed by Sept. 30
* Baer shares up nearly 4 percent, outperform sector
(Adds price details from Artio SEC filing, updated shares)
By Jason Rhodes and Lisa Jucca
ZURICH, Sept 9 (Reuters) - Swiss bank Julius Baer started moves to list its U.S. asset management arm Artio in New York, cashing in on higher equities markets to provide a timely boost for its acquisition war chest.
Switzerland's largest specialised wealth manager had often said it was planning to list Artio once equity markets firmed and that an initial public offering (IPO) could come in the third quarter.
Artio sees an IPO of 23.4 million shares at $24-$26 per share, valuing the unit at $1.44-$1.56 billion, it said in a U.S. Securities and Exchange Commissionn filing, corresponding to about 3 percent of its assets under management of 51 billion Swiss francs ($48.8 billion) at June 30.
"The performance of the markets had made this step impossible until now, so the carrying out of the IPO should basically be welcomed," ZKB analyst Andreas Venditti said on Wednesday, adding Baer could use the cash for acquisitions or share buybacks.
Baer shares were up 3.8 percent at 56 francs at 1248 GMT, outperforming a 0.7 percent rise in the DJ Stoxx European banking index.
Baer, which already has a strong capital base, has made no secret it is looking for acquisition opportunities.
Proceeds from Artio, whose IPO is scheduled to be completed by Sept. 30, could be timely given Baer is said to be the frontrunner to buy ING's Asian and Swiss private banking operations.
"For those with a positive view on the equity markets Julius Baer offers an excellent way to play rising markets," said Helvea analyst Peter Thorne.
STREAMLINING
Baer will sell 21 million shares, halving its holding in Artio to 35 percent and bringing in between $504 million and $546 million at the price given in the SEC filing.
Artio founders Richard Pell and Rudolph-Riad Younes will sell 1.2 million shares each, cutting their holding to 26 percent from 30 percent. The IPO has a 15 percent over-allotment option for a further 3.51 million shares.
Artio's stock market listing is part of a wider streamlining of the Swiss financial group, which said in May it was planning to split and list its private bank and asset management operations separately, a move investors welcomed.
Baer would not comment on Wednesday on how the proceeds of the IPO would be divided between the two new companies ahead of an announcement on the proposed split on Sept. 25.
Goldman Sachs is global coordinator and bookrunner for the proposed offering, Julius Baer said. Merrill Lynch, Pierce, Fenner & Smith Incorporated are acting as co-lead manager, and Deutsche Bank, UBS and Keefe, Bruyette & Woods are acting as co-managers for the offering. (Editing by Dan Lalor/Will Waterman) ($1 = 1.046 Swiss francs)