CHRONOLOGY: Key dates in UBS past since Arnold left as CEO

(Reuters) - Pressure on beleaguered Swiss bank UBS AG (UBSN.VX) to break up intensified as activist investor and former chief executive Luqman Arnold demanded to shake up its governance and structure.

Following are key dates in the bank's recent history from the moment Arnold was ousted as Chief Executive.

2001

December 2001 - Luqman Arnold is ousted as CEO after only eight months following a dispute over strategy with Chairman Marcel Ospel. He is replaced by Peter Wuffli.

2002

April 2002 - UBS asset management companies are united under a single global brand, UBS Global Asset Management.

November 2002 - UBS announces the sale of its 91.15 percent equity stake in Hirslanden Holding AG.

2003

April 2003 - Acquires Lloyds Bank S.A., the French wealth management business of the British bank Lloyds TSB, significantly increasing the number of UBS clients in France.

September 2003 - It announces the acquisition of the U.S. prime brokerage operations of ABN AMRO.

October 2003 - UBS Wealth Management AG agrees to acquire the private client business of Merrill Lynch in Germany, expanding the bank's European wealth management business.

2004

May 2004 - UBS launches its Private Wealth Management Group for the U.S. market, developing products and services for ultra high net worth individuals.

November 2004 - UBS (Luxembourg) S.A. and American Express Bank (Luxembourg) S.A. reach an agreement for UBS to acquire American Express Bank's private banking activities in Luxembourg.

- UBS agrees to acquire the wealth management operations of Dresdner Bank Lateinamerika and of Julius Baer in North America.

2005

June 2005 - In Germany, Wealth Management, Investment Bank and the distribution arm of Global Asset Management are merged into one company called UBS Deutschland AG.

-- It announces the integration of its two wealth management businesses under the name, Global Wealth Management & Business Banking.

December 2005 - UBS completes the sale of its Private Banks & GAM unit to Julius Baer.

2006

April 2006 - UBS says it will acquire the Private Client Branch Network of Piper Jaffray Companies, enhancing its wealth management presence in the Midwest and Western United States.

June 2006 - Dillon Read Capital Management (DRCM), UBS's new alternative investment management business, is launched.

2007

July 5, 2007 - Peter Wuffli is replaced as CEO and is succeeded by his deputy, Marcel Rohner. The sudden change, effective immediately, followed growing calls from UBS critics to bolster results, and perhaps break up the company by getting out of investment banking and focusing entirely on wealth and investment management.

October 30 - UBS reports a third-quarter pre-tax loss of 726 million Swiss francs ($624.8 million) after it took a charge of 4.2 billion francs on subprime-related losses in its fixed income investments.

December 10 - The bank announces it has written off $10 billion from the value of its subprime assets, and says it has taken measures to recapitalize the bank.

2008

January 30, 2008 - Unveils $4 billion in new write-downs, taking the total in writedowns from the subprime debacle to $18.4 billion and increasing pressure on chairman Marcel Ospel to resign.

February 27 - UBS shareholders back a 13 billion Swiss franc ($11.94 billion) capital injection from Singapore and an unidentified Middle East investor but heap scorn on the bank's chairman over the subprime losses.

April 1 - UBS writes down an additional $19 billion on U.S. real estate and related assets, causing a net loss of 12 billion Swiss francs ($12.03 billion) in the first quarter.

-- It also says it will ask shareholders for 15 billion Swiss francs via a rights issue. The total subprime writedown reaches $37.4 billion.

-- Ospel quits.

April 4 - Arnold says in a letter that UBS's reputation has been comprehensively destroyed by proprietary trading activities totally divorced from any client business.

Source: Reuters; www.ubs.com

(Writing by Jijo Jacob, Editing by David Cutler)