DUBAI, May 11 (Reuters) - Abu Dhabi state investor Mubadala posted a record income of 122 billion dirhams ($33 billion) in 2021, citing strong investment returns, the monetisation of some assets and new partnerships.

"2021 was Mubadala's strongest financial year in its 20-year history," Group CEO Khaldoon Khalifa al-Mubarak said in a statement.

The 2021 result for so-called total comprehensive income was up 69.4% on the 72 billion dirhams achieved in 2020.

Mubadala's assets under management rose to 1,045 billion dirhams, from 894 billion in 2020, it said.

It invested 125 billion dirhams during 2021 in key sectors in the United Arab Emirates and internationally, including 2.5 billion dirhams in CityFibre, Britain's largest independent fibre infrastructure platform.

It also expanded an existing partnership with Bpifrance with 4 billion euros to invest in developing French enterprises.

Mubadala is the second-biggest state fund in Abu Dhabi after Abu Dhabi Investment Authority (ADIA), which manages an estimated $700 billion in assets.

Mubadala's CEO said in late March it was pausing investments in Russia, which represent less than 1% of its portfolio, because of the Ukraine crisis.

In 2021, Mubadala listed semiconductor maker GlobalFoundries , valuing the company at nearly $26 billion in one of the biggest U.S. flotations last year. Mubadala still owns an 88% stake in the company, based on Refinitiv's Eikon data.

"As markets rose and the economy began to recover from the pandemic, we looked for opportunities to take some of our strongest companies public and invest with world-class partners in high-growth sectors and geographies," CEO Mubarak said.

Mubadala said its current five-year rolling rate of return was 12.2%.

($1 = 3.6726 UAE dirham) (Reporting by Saeed Azhar Editing by Mark Potter)