Southern Cross Media Group (ASX:SXL) received a notice from shareholder Sandon Capital (ASX:SNC) calling for a general meeting to vote on a proposal to amend the company's constitution, according to a Wednesday filing with the Australian bourse.

The proposed amendment would restrict the ability of the company to issue more than 25% of its shares without shareholder approval, a move that would be inconsistent with the proposed merger with Seven West Media (ASX:SWM), per the filing.

The company said shareholders representing over 25% of shares advised that they intend to vote against the proposal. Approval of the resolution requires a minimum of 75% of the votes cast by eligible shareholders to be in favor of the proposal, the filing said.

Southern Cross Media Group shares fell 6% in afternoon trade Wednesday, while Seven West Media shares shed 2%.