Morgan Stanley (NYSE: MS) plans to cut 1,200 jobs, or 2 percent of its global workforce, taking a severance charge of about $150 million, a source told CNBC on Tuesday.

The financial firm will reduce 470 positions in its fixed income, commodities and currencies businesses, with the remaining cuts coming from support positions across the company. The firm did not disclose its cost savings with the move, but more details may emerge in its January update.

In a memo, Morgan Stanley said the changes will result in businesses that are critically and credibly sized for the markets.

The restructuring comes amid a rough stretch for Morgan Stanley's fixed income business. For the third quarter, the firm reported that net revenue in fixed income and commodities sales and trading fell to $583 million from $997 million in the previous year.

When Morgan Stanley reported results in October, CEO James Gorman said in a statement that volatility in global markets affected "in particular our fixed-income business and our Asia merchant banking business."

Morgan Stanley shares fell nearly 2 percent shortly before noon Tuesday.

Morgan Stanley declined to comment on the record.