By Hanna Ziady, CNN Business

(CNN) -- Deutsche Bank has made an annual net profit for the first time since 2014 thanks to a bumper year in a business it has scaled back.

Germany's largest lender on Thursday reported profit of €113 million ($135.6 million) for 2020, compared to a loss of €5.7 billion ($6.8 billion) the previous year. The last time it reported an annual net profit was 2014, according to data provider Refinitiv.

The turnaround was driven by a 32% increase in revenue at its investment banking division, which has been the focus of a strategic overhaul aimed at shrinking the unit.

The investment bank was the only business unit that grew revenue in 2020, despite Deutsche Bank's plan, unveiled in 2019, to return to its roots and focus on corporate banking.

"In the most important year of our transformation, we were able to more than offset transformation-related effects and elevated credit provisions — despite the global pandemic," CEO Christian Sewing said. "We're ahead of our own expectations ... and are confident that this overall positive trend will continue in 2021, despite these challenging times," he added.

The bank's fixed income and currencies sales and trading teams achieved four consecutive quarters of double digit revenue growth last year. Investment banking also benefited from volatile markets and rising advisory income.

Deutsche Bank said it helped clients raise a record €1.7 trillion ($2 trillion) in 2020 — a 43% increase on the previous year — and led the European Union's inaugural €17 billion ($20.4 billion) social bond.

Provisions for credit losses more than doubled during the year to €1.8 billion ($2.2 billion), in line with the broader market, as banks added billions to reserves to cover bad debts arising from the pandemic.

Niklas Kammer, an equity analyst at Morningstar, said that Deutsche Bank had posted a "strong performance" but that "questions remain on the sustainability of its regained earnings power."

"That being said, concerns we initially had of Deutsche Bank undergoing its sizable restructuring program during a pandemic were misplaced and we think the group continues to right its ship," Kammer added in a note to clients on Thursday.

Righting the ship

Deutsche Bank has racked up billions of dollars in losses since 2015. For years the bank tried to compete on a broad front with Wall Street rivals such as JPMorgan Chase and Goldman Sachs.

The company has announced several major restructurings since the global financial crisis. The most recent, in 2019, included slashing 18,000 jobs, or 20% of its workforce. It also shuttered its equities sales and trading division, while trimming its rates division.

Sewing told analysts on an earnings call that Deutsche Bank reduced its headcount by 8% in 2020. That helped it to hit its cost targets, he added, and it achieved a €3.3 billion ($4 billion) reduction in two years after cutting expenses for 12 consecutive quarters.

The strong performance from its investment bank offset revenue declines in its corporate bank, private bank and asset management division.

In the latest sign of the challenges facing European lenders, including record low interest rates and recession, Deutsche Bank's main domestic rival Commerzbank said last month that it plans to slash its workforce by 10,000 and close 340 branches in Germany by 2024.

Alongside a major restructuring, Deutsche Bank is also distancing itself from former US President Donald Trump. Trump has several outstanding loans with the bank, according to financial disclosure documents he was required to file as president.

Deutsche Bank has revealed in US regulatory filings that the bankers responsible for the relationship with Trump and his son-in-law Jared Kushner resigned last year following allegations related to an unauthorized real estate deal.

— Will Godley, Charles Riley and Julia Horowitz contributed reporting.