Navient Corp. (NAVI - Get Report) received a buyout offer worth about $3.2 billion but rejected the offer saying it "substantially undervalues" the servicer of student loans.

The board of Navient voted Monday to turn down the proposal of $12.50 a share from hedge fund Canyon Capital Advisors LLC and private-equity firm Platinum Equity Advisors LLC, The Wall Street Journal reported Monday. Navient issued a confirmation.

"Navient's Board, in consultation with its financial and legal advisors, has carefully reviewed the expression of interest and unanimously determined that it substantially undervalues the Company and is not in the best interests of Navient or its stockholders. Therefore, Navient's Board rejected the expression of interest, the company said in a statement.

The offer represented a 6.6% premium over Navient's closing price on Friday of $11.73 a share.

Navient's advisers had told Canyon it would require a price of more than $15, people familiar with the matter told the Journal. 

Navient has a market value of nearly $3 billion.

Navient shares were rising 5.9% to $12.43 on Tuesday.