The activist investor Nelson Peltz has built up a stake of nearly 2.5 percent in Bank of New York Mellon.
On Monday, Mr. Peltz’s hedge fund, Trian Partners, disclosed that as of March 31, it had a 0.8 percent stake in the bank, according to a filing with the Securities and Exchange Commission. The hedge fund requested permission from the regulator to keep the stake confidential, the filing said. The disclosure comes as the confidentiality period expired.
Trian has continued to buy shares in Bank of New York Mellon, bringing its total ownership to 28.9 million shares, or a $1.05 billion, as of last week, Andrea Calise, a spokeswoman for the hedge fund, confirmed.
The disclosure of the initial stake sent shares in the bank up 3.3 percent, to $37.44, in morning trading on Monday.
The hedge fund recently contacted the bank to say it was interested in having a discussion about ideas to “drive long-term growth and enhance shareholder value,” Ms. Calise said.
“Trian is a respected investment firm,” said Kevin Heine, a spokesman for Bank of New York Mellon. “We look forward to engaging with them as we do all our investors.”
Mr. Peltz’s Trian has a history of buying shares in companies and then pressing management to improve performance. He has taken on Wendy’s, Ingersoll-Rand and Mondelez International, which owns brands like Ritz and Cadbury.
Trian has also engaged with banks before. In 2011, it took a stake in State Street, urging the bank to split off its money management unit. While it did not sell the unit, it did cut costs and return capital to shareholders. Trian sold its stake in State Street last November.
An earlier version of this article misspelled a company name. It is Mondelez International, not Mondolez International.