According to a source familiar with the situation on Sunday, an investor consortium led by Brigade Capital and Arkhouse Management has made a $5.8 billion offer to take department store operator Macy’s (M.N.) private.

The person added that on December 1, two investment firms with a specialty on real estate, Arkhouse Management and Brigade Capital Management, filed a proposal to purchase the Macy’s shares they do not currently own for $21 per share. The offer was first published earlier on Sunday afternoon by The Wall Street Journal.

The offer for the Bloomingdale’s parent is a 20.76% premium from its closing at $17.39 on Friday.

Macy’s shares were trading at $20.13, or up nearly 16% on Monday. Fellow department store operators Kohl’s (KSS.N) and Nordstrom (JWN.N) also rose about 6%.

The investor group already has a big stake in Macy’s through Arkhouse-managed funds and has discussed the proposal with the department store chain, whose board subsequently met to discuss the offer. It is not clear how the retailer views the proposal, the person familiar with the matter said.