Marathon Oil Corp., Houston, added Baird Asset Management's Midcap Fund to the lineup of its 401(k) plan, the company disclosed in its 11-K filed Wednesday.
The Baird fund was added in August 2016 and replaced a Morgan Stanley Investment Management midcap growth equity option.
The reason for the change could not immediately be learned.
Also effective Dec. 30, a Marathon Oil stock option was frozen, meaning participants' future contributions could no longer be invested in the stock option.
"Any individual company stock poses a greater potential investment risk than investment in mutual funds and other diversified investment options, so this change was made to help participants reduce risk in their plan accounts," Marathon Oil said in the 11-K.
As of Dec. 31, the Marathon Oil Co. Thrift Plan had $988 million in total assets. As of the same date, $38.3 million was invested in the Marathon Oil stock option.
A Marathon Oil spokeswoman could not immediately be reached for additional information.