The NZX50 fell 33 points to 4015 on turnover of $178 million on Tuesday.
Chorus was down 13 cents at $2.78 after a proposal by the Commerce Commission on Monday to cut what it can charge retail providers for broadband and voice services.
Telecom was down 4.5c at $2.275, Fletcher Building fell 7c to $7.91, and Contact Energy was down 2c to $5.37.
Sky TV Network dropped 11c to $5.15, Fisher and Paykel Healthcare remains unchanged at $2.61, and The Warehouse was down 1c to $3.12.
Xero dropped 70c to $7, Vector was down 5c to $2.60, Hallenstein Glasson was unchanged at $5.08, as was Ryman at $4.15, and Goodman Fielder was down 1c to 86c.
Restaurant Brands was down 1c to $2.69, and Mainfreight fell 14c to $10.96.
At 5.05pm, the NZ dollar was trading at 82.25 US, 78.75 Australian, 51.10 pence, 67.53 yen, 0.6297 euro and the Trade Weighted Index was at 73.41.