April 12 (Reuters) - State Street's assets under management for the first quarter rose by nearly 20% helping it post an increase in fee earned from managing clients, the company said on Friday, sending its shares up 4.2% in premarket trading.

State Street services and manages investments for high-net-worth clients that include governments, institutions and investment companies. The bank had record $4.3 trillion in assets under management (AUM) at the end of the March quarter, up from $3.6 trillion last year.

However, its quarterly profit fell nearly 16% to $463 million, or $1.37 per share, due to a 6% rise in its expenses, including $130 million to replenish the Federal Deposit Insurance Corporation's insurance fund.

In line with broader industry trends, State Street's net interest income (NII) in the quarter declined 6.5% to $716 million in the quarter ended March. 31, from a year earlier.

CEO Ron O'Hanley said the bank's fee revenue growth reflected robust performance across its Global Advisors and Front office solutions businesses, which, along with growth in servicing fees, more than offset lower trading revenues as volatility remained muted. (Reporting by Jaiveer Singh Shekhawat in Bengaluru; Editing by Shailesh Kuber)