* Santander Brasil to price IPO in Sao Paulo, New York
* Offer may total $8.91 bln, largest U.S. IPO in 18 months
* Shares to start trading Oct. 7
SAO PAULO, Oct 6 (Reuters) - Banco Santander's Brazilian unit will price its initial public offering on Tuesday in a closely watched stock sale that could fetch up to 15.6 billion reais ($8.91 billion), making it a record for Brazil and the largest IPO on a U.S. exchange in 18 months.
The bank
The IPO would cap months of torrid activity in Brazil's stock market, which had 21.76 billion reais in share sales since late June. The offering may also benefit from growing appetite for emerging market securities that has helped push the benchmark Bovespa index <.BVSP> 68 percent higher so far in 2009.
Banco Santander (Brasil) SA, a unit of Spain's Santander
The IPO would be the largest ever for a Brazilian company
and the biggest in the world since Visa Inc's
Santander is the third largest private-sector bank in
Brazil by assets, with a 10.2 percent market share, behind Itau
Unibanco
The bank has expanded with six takeovers in Brazil the past 12 years, including the acquisition of Sao Paulo state bank Banespa in 2000 for 7 billion reais.
Santander purchased ABN Amro's Banco Real unit in Brazil in 2008 as part of its 70-billion-euro bid for the Dutch firm with Royal Bank of Scotland and Belgian-Dutch Fortis.
The Brazilian unit has emerged as one of the most profitable parts of Santander, accounting for 20 percent of its net income in the first half of 2009.
Banco Santander expects net IPO proceeds of $6.8 billion, and will use about 70 percent of the funds to expand its network of branches and install automatic teller machines. It will also use some of the proceeds to improve its capital ratios, according to its U.S. regulatory filing.
Banco Santander had 3,603 full-service branches and smaller service centers in Brazil as of December 2008.
In the six months ended in June 2009, Santander's Brazilian unit reported net interest income of $5.5 billion and profits of $1.25 billion. ($1=1.75 reais) (Reporting by Elzio Barreto and Phil Wahba in New York; editing by Gunna Dickson)