(Updates Sept. 26 item with new entries, updated graphic)

By Tom Sims

FRANKFURT, Dec 18 (Reuters) - UniCredit has

raised its stake in Germany's Commerzbank to 28% with

new derivative contracts as its bid for smaller domestic peer

Banco BPM faces hurdles.

Commerzbank has, like some other banks, had a rocky history

with big mergers and acquisitions over the years.

These are some of the key moments:

1870-1970s

The bank was founded in Hamburg and later moved to Berlin.

It relocated to Frankfurt in 1970 as one of Germany's leading

banks, focusing on retail and corporate customers.

1970s

Expands to London and New York, and other European capitals.

2008

Agrees to buy Dresdner Bank, one of Germany's biggest banks,

from insurer Allianz in a $14.5 billion deal.

Commerzbank is Germany's first commercial bank to turn to

the government for capital during the global financial crisis.

2009

In a bailout, Germany takes a stake of 25% plus one share in

Commerzbank in return for an additional 10 billion euro ($11.13

billion) capital injection.

2011-2013

European debt crisis continues.

2016

Commerzbank embarks on a multi-year restructuring.

2017

U.S. investor Cerberus builds a stake controlling 5% of the

German bank's voting rights.

UniCredit tells Berlin it is interested in eventually

merging with Commerzbank, Reuters reported, a combination that

would create one of Europe's biggest banks.

BNP Paribas' then Chairman Jean Lemierre dampened rumours

that it was interested in a tie-up with Commerzbank.

2018

Commerzbank drops out of blue-chip DAX index.

Deutsche Bank describes as "fictions" media reports

suggesting that Germany's biggest bank might seek a tie-up with

Switzerland's UBS or Commerzbank.

2019

Cerberus says it is open to a merger between Germany's two

biggest lenders.

Deutsche Bank and Commerzbank hold merger talks, but call

them off weeks later.

UniCredit engages investment bankers to advise it on a

potential bid for Commerzbank.

Commerzbank's supervisory board approves plans to cut

thousands of staff and close a fifth of its branches after the

failed merger with Deutsche Bank.

2020

In a u-turn, Commerzbank says that it would not sell its

Polish subsidiary mBank, citing poor market conditions.

Cerberus calls on Commerzbank to appoint two of its nominees

to the supervisory board, cut costs and adopt a new strategy.

Commerzbank's chairman and chief executive step down, bowing

to demands from Cerberus.

2021

Commerzbank's new CEO, Manfred Knof, wants to cut 10,000

jobs and close hundreds of branches as part of a strategy

revamp.

Knof says Commerzbank is working to remain independent.

2022-2023

UniCredit CEO Andrea Orcel approaches Knof about a potential

deal in early 2022, before the Ukraine war, people with

knowledge of the matter told Reuters.

Commerzbank returns to profit and rejoins the DAX.

2024

Jan. 23 Knof plays down prospects of a possible merger with

Deutsche Bank, saying he was striving to keep the bank

independent.

May 15 Commerzbank wants to "tone down" merger speculation

and is entirely focused on its current strategy, which is the

"best prerequisite" to stay independent, Knof said.

Sept. 3 Germany intends to reduce its 16.5% stake as

Commerzbank is stable again years after its rescue, the

government says.

Sept. 10 Commerzbank says Knof would not seek another term

when his contract ends in December 2025, as the German

government begins to sell some of its shares.

Sept. 11 UniCredit approaches Commerzbank about exploring

merger talks, a source with knowledge of the matter said, after

the bank bought a 9% stake. Commerzbank's management discusses

how to keep the lender independent.

Sept. 13 German government officials and UniCredit bankers

hold talks, Reuters reports.

Sept. 16 Knof snubs UniCredit's overtures, saying he had his

own plans for the bank and hoped it could stay independent.

Sept. 17 Bettina Orlopp, Commerzbank's finance chief, says

the German government should retain its Commerzbank stake.

Sept. 18 Commerzbank prepares to put Orlopp in charge of

talks with UniCredit, two people with knowledge of the matter

said.

Sept. 20 Germany says it would not sell any more shares in

Commerzbank for now.

Sept. 23 German Chancellor Olaf Scholz calls UniCredit's

move to acquire a possible 21% stake in Commerzbank "an

unfriendly attack" .

Sept. 24 Orlopp will take over as CEO, the bank announces.

Sept. 26 Commerzbank and UniCredit will hold a first round

of talks on Sept. 27, Orlopp says, as Commerzbank burnishes its

independent strategy.

Oct. 1 Orlopp, on her first day as CEO, tells staff she

wants the bank to remain independent.

Nov. 6 Germany's ruling coalition collapses, raising

questions about whether the government could still fend off

UniCredit's approach.

Nov. 12 Commerzbank is considering buying a mid-sized German

bank as part of its defence strategy, people tell Reuters.

Nov. 25 UniCredit launches a bid for domestic peer Banco

BPM, which Orcel said would take precedence over any potential

move on Commerzbank.

Dec. 18 UniCredit announces an increase in its stake in

Commerzbank via derivatives to around 28%.

($1 = 0.8982 euros)