Scottish, UK and international news will be brought together in the half-hour programme, which will go out each week-day evening at 7pm from early next year.
The broadcaster said the new show, STV News Tonight, will reflect the "unique news agenda of a devolved nation" using its 160-strong team across Scotland, as well as ITV’s international and UK news resources.
The plans have emerged in the wake of the BBC confirming it is pressing ahead with plans for a new early evening broadcast in the wake of the corporation's new Royal Charter being published.
BBC Scotland has been making different pilot broadcasts of what a potential "Scottish Six" show could look like over the last few months.
However a final decision on which, if any, option will get the green light is not expected to be made until the end of this year.
BBC Scotland announced the cancellation of its late-night current-affairs show Scotland 2016 in June as part of an ongoing overhaul of its news programming. The programme, launched in the run-up to the independence referendum, had lost out in a ratings battle with STV's Scotland Tonight show.
The launch of STV News Tonight will coincide with the rebranding of the broadcaster's network of local channels under a single "STV2" banner.
Bobby Hain, director of channels at STV, said: “We’re committed to delivering choice for our consumers and we believe there is an appetite for a nightly news programme that combines Scottish, UK and international news.
"STV News Tonight will be produced and presented live from Glasgow, drawing on the news-gathering resources of both STV news across Scotland and ITV news worldwide.
"It will complement the existing schedule of bulletins with an editorial brief that is fresh and distinctive."
Gordon Macmillan, head of news at STV, added: “This is a programme whose merits have been long-debated in Scotland.
"I’m delighted that it is STV that will bring this landmark new programme to Scotland’s screens.
"Viewers can look forward to yet another TV first: the best of Scottish, UK and international news in a single programme and presented in the way that solely meets the needs of a Scottish audience.”