(Reuters) - Legg Mason Inc said on Wednesday it will incur about $4 million in charges for the quarter ended September 30 to cover the costs of the separation agreement with its departing chief executive, Mark Fetting.

The Baltimore-based asset manager said last week that Fetting will step down as chief executive and chairman on October 1. He will remain as a consultant through the end of the year.

In a securities filing on Wednesday, Legg Mason said under the separation agreement Fetting will receive payments totaling $2 million over 15 months, health insurance, and outplacement services worth up to $25,000. He also will remain entitled to 111,548 unvested restricted shares of stock.

The benefits are subject to limits on Fetting's activities, the filing said, such as not allowing soliciting clients of Legg Mason.

A search to replace Fetting will consider both internal and external candidates, Legg Mason has said.

(Reporting by Ross Kerber; Editing by Leslie Adler)