The move will see 25 employees lose their role as the company predicts the channel cancellation will save £1 (€1.14 million) a year.
The broadcast, digital and production divisions will also each have their own managing director and KPIs.
"More under 55s browse STV news online than watch our regular bulletins", it said.
The STV News 2020 plan will, the broadcaster said, ensure it remains the best news service in Scotland while delivering significant cost savings.
Pitts was appointed in January this year after leaving ITV, where he was managing director of online, pay TV, interactive and technology. Along with today's announcement the Chief Technical Officer Alistair Brown announced his departure and Paul Hughes who was Head of Programmes at STV has announced on LinkedIn that he had already made a decision to leave the company.
The five local TV licences that were part of STV2 will be sold to That's Media, while wider restructuring of the news operation will result in a further 34 job losses and around £1m cost-cutting. "The loss of 34 jobs in news and the closure of STV2 with the ending of the flagship "STV News Tonight" Scottish and worldwide news programme will lead to a massive reduction in the breadth and depth of news coverage viewers in Scotland now enjoy". The decision to bring this channel to an end is no reflection on the abilities or professionalism of the staff.
Several jobs on the digital news desk are also likely to go. "The NUJ will work with STV management to try to reduce the number of redundancies required, and we are resolved that compulsory redundancies will be strongly opposed".
Pitts said: "This is a positive vision for STV that will re-establish the company as a creative force in Scotland and beyond".
"Our de-risked broadcast business is resilient and provides the engine room for STV's growth".
"We will exploit STV's unique producer-broadcaster status to attract the best creative talent and showcase new formats and ideas for the United Kingdom and global markets", he added.
"News is fundamental to the STV brand and we remain committed to offering the best news service in Scotland".
Scottish broadcaster STV is shutting down its STV2 channel at the end of June, with content investment shifting to the STV main channel and STV Player.
He thanked the STV2 team for everything they had achieved.
Mr Pitts said: "We have ambitious growth plans for STV Productions which is well placed to take advantage of the surge in demand for new programming from the nations and regions".