WASHINGTON—Citigroup Inc. is increasing the base salaries of many employees—reportedly by as much as 50 percent for some workers—as it restructures their compensation amid government restrictions on bonuses.

The higher salaries are not the equivalent of annual raises because bonuses are being lowered, according to a person familiar with the matter who requested anonymity because the plans have not been made public.

The person said the changes would not affect the amount of an employee’s compensation. By shifting the mix in compensation packages, the change could allow Citi to pay most employees as much as they received in 2008 while adhering to bonus caps. The person said the employees included traders, who tend to be compensated more heavily with bonuses, and middle-and lower-level managers whose compensation is more heavily weighted toward salaries.

A New York Times report Wednesday said some employees’ salaries will rise as much as 50 percent because of the change in compensation structure.

The 100 highest-paid employees at Citi will not be part of the bank’s revised compensation program because of the government’s additional review over that group’s pay.