The company was now "free and able to compete without the one arm tied behind our back" after years of "undue" Government regulation, he said.
Following operational separation in 2008, Reynolds said, Chorus had already been operating at arm's length from Telecom.
"Maybe Mark [Ratcliffe] had sometimes felt like he was in the granny flat out the back but today Chorus are very definitely moving to their new place," Reynolds said.
Opening with drums and song - which Reynolds joked was a "great New Zealand chorus" - the ceremony closed with confetti, streamers and performers in orange high-visibility vests leaving Telecom's building carrying office-document boxes.
Since May, Telecom and Chorus have been busily preparing to split up and completed the process yesterday.
The demerger sees Chorus become a public company to take part in the Government's ultra-fast broadband scheme and roll out high-speed fibre internet cables in 24 towns and cities over the next eight years.
Since the split, Chorus is now a wholesaler and own 130,000km of copper lines, more than 27,000km of fibre cables and more than 500 telephone exchanges.
Telecom is a standalone retail business but keeps hold of its mobile network.
In the lead-up to the demerger, Chorus and Telecom listed separately on both the NZX and the ASX last week.
At the close of the first day of trading on the local market, Chorus closed at $3.21 and Telecom at $2.025.
Chorus reached a high of $3.31 over the past week and closed yesterday at $3.29, down 2c.
Telecom dropped to a low of $1.935 since the separate listings, and closed yesterday at $2.03 up 2.01 per cent.
Using analyst calculations, the combined value of both companies is more than Telecom before the split listings.
The split is one of the country's biggest corporate shakeups and was voted through with a resounding majority by Telecom shareholders on October 26.
Staff cheered as the confetti rained down yesterday.