SkyCity rose 3.7 per cent to $3.90. The Australian Financial Review's Street Talk reported investors and bankers were looking at a tie-up between SkyCity and its rival The Star Entertainment Group.
The casino operator's shares fell last week after it posted weaker first-quarter revenue.
Genesis Energy was the worst performer on the index, down 1.8 per cent to $1.935, while Heartland Bank dropped 1.3 per cent to $1.51 and Vista Group International fell 1.3 per cent to $6.05.
Outside the benchmark, Wynyard Group remained in last week's trading halt at 21.5 cents. The board has appointed voluntary administrators after the intelligence software developer gave up on drawing a $10 million loan from major shareholder Skipton Building Society or trying to raise new capital.
Auckland-based Wynyard halted trading in its shares while it investigated ways to tap a standby loan facility with Skipton however it said Tuesday that drawing down the loan or raising new debt or equity wasn't "in the best interests of the company, its shareholders or other stakeholders".
The shares have plunged 88 per cent so far this year as the software developer burned through cash and struggled to deliver on revenue guidance.
Abano Healthcare dropped 0.1 per cent to $8.09. The Australasian dental centre and radiology operator told shareholders at its annual meeting it expects to lift first-half profit by up to 50 per cent in 2017 with increased earnings driven by dental acquisitions.
Auckland-based Abano, which owns the Lumino the Dentists chain in New Zealand and Maven Dental Group in Australia, is investing to grow its chain of dental businesses.