Manchester's museum of science and industry, MOSI, is to merge with London's National Science Museum, in January.
The museum, which was due to lose all government funding by 2015, will join the National Museum of Science and Industry (NMSI) group.
Interim chairman Peter Fell said the move would "secure the future of MOSI".
The NMSI group also includes York's National Railway Museum and National Media Museum in Bradford.
In November, a spokesman for NMSI said it was talking to MOSI and the Department of Culture Media and Science (DCMS) about the possibility of a merger.
Mr Fell said the talks had come to a positive conclusion to "allow us to continue to celebrate Manchester's unique contribution to science and industry with the backing of the NMSI group".
NMSI Chair Douglas Gurr said: "MOSI holds exceptional collections housed in a landmark location.
"NMSI is delighted that such an important resource, both for Manchester and the country, is joining the group."
The museum, which employs 121 staff including part-timers and casual staff, has been looking to secure its financial future since a decision in November 2010 by the DCMS to withdraw funding for regional museums.
It showcases the story of how Manchester and north-west England led the world during the industrial revolution and subsequent science and technology innovations.
It is one of the most popular attractions in the North West, drawing up to 800,000 visitors a year.
Sir Richard Leese, leader of Manchester City Council, said the deal was "excellent news for one of the city's flagship museums".
"I'm sure MOSI's merger with NMSI will be mutually beneficial and further strengthen our thriving museum sector, which makes a major contribution to the cultural and economic life of the city," he said.