President of UBS EMEA Ulrich Koerner, who has been "instrumental" in reforming its asset management division since 2014, and co-president of UBS global wealth management Martin Blessing will step down from their roles in October.
Koerner is also president of the bank's asset management division, which will now be led by head of investments for UBS Asset Management Suni Harford.
However, Koerner will stay on as a senior adviser to the group CEO until at least 31 March 2020 "to support the group with several ongoing key initiatives", the bank said.
In a statement UBS said Koerner presided over its asset management division at a time when the industry "was undergoing its most radical change in decades", and he was responsible for its repositioning from a "fragmented multi-boutique structure to an effective and globally integrated business".
It added: "This brought UBS asset management back on a sustainable growth path driven by significantly improved investment performance.
"He was instrumental in designing and implementing the transformation of UBS's operating model, establishing a global service and control organisation which unlocked significant synergies for the firm."
Koerner's replacement Harford, who will also join the UBS group executive board, joined the firm in 2017 after nearly 25 years at Citigroup, latterly as the regional head of markets for North America. She has also served in the investment banking arm of Merrill Lynch.
UBS said in a statement: "She is a strong leader with an excellent track record and broad experience across the industry, including research, client coverage and risk management."
Blessing, who will remain with UBS until 31 December 2019 to ensure a smooth transition, will be replaced by Iqbal Khan who joins the firm from his role as CEO of International Wealth Management.
Outgoing co-president Blessing has been in the role since February last year, during which time UBS said he "played a crucial role in the smooth and successful combination of our international and US wealth management businesses, reaching the planned synergies and driving initiatives for sustainable growth".
Meanwhile, incoming Khan was also a member of the executive board at Credit Suisse from 2015 to 2019, during which time he developed the firm's international wealth management division and drove growth and profitability in the business.
Elsewhere, group COO Sabine Keller-Busse will succeed Koerner as president of UBS EMEA.
Group CEO Sergio Ermotti said in a statement that Koerner had made a "significant contribution" to the bank's "successful strategic transformation and its execution after the financial crisis".
He added: "I am looking forward to having Suni and Iqbal join the group executive board.
"Both of them bring strong leadership and people skills along with a track record of successful execution.
"They are great additions to the team and will help us drive sustainable growth and profitability for UBS."