* Investor RBR wants to split Credit Suisse into 3 parts
* RBR CEO says trying to raise at least $1 bln to buy more shares
* Fund also wants Credit Suisse to build new IT platform
* RBR CEO speaking at a conference in New York
ZURICH, Oct 20 (Reuters) - Activist investor RBR Capital Advisors wants to expand its stake in Credit Suisse to 1 billion Swiss francs ($1 billion), as the hedge fund pushes to spin off the Swiss lender's investment bank and asset management business.
RBR has so far invested almost half its 250 million francs in assets to buy roughly 0.2 percent of Credit Suisse, which it believes would be worth twice as much if the bank focused solely on wealth management and its Swiss business.
RBR Chief Executive Rudolf Bohli is trying to drum up fresh cash to take a larger position in Credit Suisse, Switzerland's second-biggest bank.
"Currently the RBR fund has invested 100 million," Bohli told Reuters in a telephone interview. "We aim to raise an additional 900 (million)."
The boutique Swiss hedge fund went public this week with its campaign to split up Credit Suisse into three parts: an investment bank, an asset management group and a wealth manager accommodating its Swiss retail and corporate banking operations.
Success hinges on winning support from other investors, with Bohli saying his firm has signed non-disclosure agreements with 150 investors, mainly non-Credit Suisse shareholders.
RBR, which has had mixed success in previous activist campaigns against asset manager GAM and airline catering company Gategroup, has not set a timeframe for its campaign.
However, Bohli said the fund would abandon the effort if shareholders are not receptive to the proposals.
"BANKS ARE DINOSAURS"
In a presentation prepared for the JP Morgan Robin Hood Investor Conference in New York, Bohli also pushed for Credit Suisse to completely overhaul its IT infrastructure.
"Overall, banks are dinosaurs," Bohli said in the interview before the conference. RBR argues Credit Suisse's IT platform should be abandoned in favour of a new, yet-to-be built system. RBR does not have an estimate for how much the new system would cost.
Investors and analysts have so far taken a sceptical view on the chances of success for RBR, which has received input from Gael de Boissard, a former Credit Suisse investment bank co-head who left the bank in 2015.
In response to RBR's campaign, the bank has said it is focused on implementing its current strategy, which emphasises wealth management, particularly in Asia Pacific, supported by two investment banking divisions.
Credit Suisse is around two years into CEO Tidjane Thiam's painful three-year restructure, which has yet to bear fruit.
RBR believes Credit Suisse is worth more split up into three separate businesses and wants to float the investment bank operations which sit in London and New York, and the asset management division.
The core of Credit Suisse would then be the wealth management business and its Swiss universal bank, which houses retail, corporate and investment banking operations.
Bohli said the fund's plan "has the potential" to double Credit Suisse's share price within 18 to 24 months. Credit Suisse's current market capitalisation is around $40 billion.
($1 = 0.9815 Swiss francs)
(Editing by David Holmes)