* Santander nets 1.43 bln euros on Brazil arm IPO
* New Brazil shares seen opening flat to higher
* Investors take profit after rally in group
By Elisabeth O'Leary
MADRID, Oct 7 (Reuters) - Spanish bank Santander will make a 1.43 billion euro ($2.10 billion) capital gain on the listing of its Brazilian unit, it said on Wednesday, lining it up to reap the rapid growth expected in Brazil and underpinning its capital base.
Santander, the euro zone's biggest bank, said it would use its earnings on the Brazil share sale to boost generic provisions. That will build strength with which to stave off the effects of the global recession, which has seen unemployment and bad debts rise, especially in Spain.
The transaction will simultaneously increase the group's core capital, its buffer against unexpected losses, by 0.60 percentage points. Core capital was at 7.5 percent at end-June.
Analysts were overwhelmingly positive on the Brazil deal.
"Brazil is a major driver for Santander ... (and) could not be in a sweeter spot, we think. Brazil has gone through one of the mildest recessions in the world and is expected to grow strongly going forward," said Arturo de Frias, analyst at Evolution Securities.
Shares in Santander were taking a breather following the 14.1 billion reais ($8.05 billion) record initial public offering in its Brazil unit. They were down 1 percent to 11.050 euros at 0850 GMT, having risen about 7 percent since last Friday.
De Frias has a target price of 16.60 euros on Santander and believes the bank's potential in Brazil is not factored into the group's share price.
Banco Santander Brasil sold 600 million units at a price of 23.5 reais each.
Some analysts say the size of the float, increased from an initial forecast, will likely prevent the stock from having a robust first day jump on Wednesday.
The bank had filed to sell 525 million units, with each unit representing 55 common shares and 50 preferred shares, but the offering was increased 75 million units to meet demand from investors.
But others see the new shares getting a good start and rising as much as two percent, thanks to the bright prospects for growth of banking services in Brazil.
Santander runs the third largest private-sector bank in Brazil by assets, with a 10.2 percent market share, behind Itau Unibanco and Bradesco.
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. (Editing by Rupert Winchester)