* IPO could bring up to $4.9 bln; Brazil's biggest-ever IPO

* Brokerages had released unapproved advertising material

* Brazil regulator says banning was appropriate response
(Recasts first sentence, adds comments from Brazil securities
regulator)

By Elzio Barreto and Alberto Alerigi Jr.

SAO PAULO, June 24 (Reuters) - VisaNet, the Brazilian
affiliate of credit card network Visa Inc (V.N: Quote, Profile, Research), said that 19
brokerages have been banned from participating in its massive
initial public offering because they had released unapproved
advertising material about the sale.

VisaNet's IPO could bring 9.7 billion reais ($4.9 billion)
if underwriters exercise their option to sell additional shares
to meet demand. That would make it Brazil's largest ever and
among the biggest in the world the past year.

Among the prohibited brokerages are Bradesco SA Corretora
and Agora Senior Corretora, both units of Brazil's
second-largest private-sector bank Bradesco (BBDC4.SA: Quote, Profile, Research), as well
as ABN Amro Real and ICAP do Brasil.

Bradesco BBI, the investment banking arm of Bradesco, is
the lead underwriter of the offering.

Bradesco decided to ban several brokerages, including its
own, instead of risking the postponement of the massive stock
offering, according to an official at Brazil's securities
regulator, known as CVM.

He said the regulator would not block the VisaNet IPO
because Bradesco made an appropriate decision by prohibiting
the brokerages from taking part.

"From our point of view that was a suitable response," said
Felipe Claret da Mota, head of registrations at Brazil's CVM.

"In a process where we see some irregularities, we could
suspend the offering. We see that Bradesco was able to stop the
problems."

Four other brokerages had already been banned from the
offering because they released advertising material that
Brazilian securities regulators had not approved.

Brazilian brokerage Ativa sent a statement to its clients,
saying their orders also had been canceled. The company said it
was recognized for "totally conforming to market rules and
regulations" and that it was looking into what happened.

ICAP do Brasil, a unit of British inter-broker dealer ICAP
Plc (IAP.L: Quote, Profile, Research), said it had not received an official statement
from the Brazilian securities regulator. Bradesco did not
return phone calls seeking comment.

Shareholders of VisaNet (VNET3.SA: Quote, Profile, Research), whose formal name is
Cia Brasileira de Meios de Pagamento, plan to sell at least
477.67 million shares at 12 reais to 15 reais each.

The company is controlled by Bradesco, with a 39 percent
stake; Banco do Brasil (BBAS3.SA: Quote, Profile, Research), with 31 percent; and Spain's
Santander, with 14 percent. Visa Inc unit Visa International is
also part of the controlling group, with a 10 percent stake.

Bradesco, Banco do Brasil, Visa Inc, Santander and the
Brazilian unit of HSBC Holdings Plc (HSBA.L: Quote, Profile, Research) would be among the
VisaNet shareholders selling stock in the credit card
processing company and would receive proceeds from the sale.

($1=1.981 reais)
(Reporting by Elzio Barreto; editing by Matthew Lewis)