The newspaper, which launched its compact edition in London last November, has put the move down to the circulation successes of the gradual roll-out of the new format.
The move will also reduce the cost of producing both broadsheet and tabloid editions.
In a statement, Paul Hayes, Times Newspaper general manager, said: "We tested the market and our sales in Northern Ireland, Scotland and the West Country rose significantly when we became a compact-only newspaper in those areas.
"The move is a response to clear reader demand and we look forward to a compact future."
According to the most recent Audit Bureau of Circulation figures, the paper's sales have risen by 32% in the Irish Republic, which was the first area to go all-compact.
The Independent was the first paper to launch a compact edition in September 2003, dropping its broadsheet edition entirely in May this year.
The Guardian is also planning to change format, with a 50m investment in switching to a three-quarter sized Berliner format in 2006.
Story by Josh Brooks