Oct 11 (Reuters) - BNY's profit jumped 16% in the

third quarter on higher investment services fees as assets under

its custody and administration exceeded the $50 trillion mark

for the first time, the world's largest custodian bank said on

Friday.

The bank's fees, typically calculated as a percentage of the

assets under custody, benefited from a market rally that boosted

their value as well as acquisition of new clients.

Economic resilience and expectations of an interest rate cut

cycle, which began in the final month of the quarter, prompted

clients to keep up their investment activities and bolstered

BNY's bottom line.

Net interest income (NII) - the spread between earnings from

assets and costs on liabilities - also jumped 3% as yields from

BNY's bond investments offset the impact of higher deposit

costs. Analysts had expected a 1.3% drop in NII, according to

estimates compiled by LSEG.

Profit applicable to BNY shareholders was $1.11 billion, or

$1.50 per share, for the three months ended Sept. 30, compared

with $958 million, or $1.23 per share, a year earlier.

Assets under custody and administration were $52.1 trillion,

14% higher than last year.

SECURITIES BUSINESS SHINES

Total fee revenue grew 5% from a year earlier to $3.40

billion. Asset servicing - the unit responsible for safekeeping

and settlement of trades - fetched 5% higher revenue.

Meanwhile, issuer services, which caters to clients issuing

securities, saw a 1% jump.

As a crucial intermediary in the financial system, the

240-year-old bank's results are significant because they often

reflect broader market trends.

"Our actions to run our company better, including our

ongoing transition to a platforms operating model, are starting

to deliver progress toward our medium-term financial targets and

additional capacity to reinvest for growth," CEO Robin Vince

said.

So far this year, BNY's shares have gained 43% while peers

State Street and Northern Trust ( NTRS ) are up 15% and

8%, respectively.