Slow dealmaking and a tough economic environment are prompting the investment bank to look at its headcount, the source said.
The latest move follows another quarter in which fees from the investment banking unit fell, dragging total revenue down nearly 2% to $14.5 billion.
Last month, Morgan Stanley finance chief Sharon Yeshaya had said that "expense management" was a priority given the broader market uncertainty and elevated inflation.
Wall Street's investment banks have suffered from a downturn in deals as investors grew more cautious about volatile markets and rapidly rising interest rates.
Initial public offerings have also come to a virtual standstill as startups put off market debuts until investor sentiment improves.
M&A volumes nearly halved in the first quarter from a year earlier, according to data from Dealogic.
Morgan Stanley CEO James Gorman had said in December that the bank would make "modest" job cuts worldwide without giving an exact number.
The bank had more than 82,000 employees as of March end and the layoff will affect nearly 4% of its staff.
Bloomberg News was the first to report about the latest job cuts.
