SimplySwitch.com operates a website and call centre allowing consumers to compare prices and switch providers for services ranging from gas and electricity, to home and mobile phone, to broadband and credit cards.
It will form part of Associated's digital division, Associated Northcliffe Digital, but continue to operate independently.
Associated Northcliffe covers the online offshoots of the national and local newspapers owned by Associated and Northcliffe Newspapers, which include personal finance site Thisismoney.co.uk.
Andy Hart, managing director of Associated Northcliffe, said: "The fit with other group assets is strong, and we expect the business to work closely with a number of the group's other businesses.
"SimplySwitch is also expanding its range of personal finance products, and will be a key component of Associated Northcliffe's personal finance offering."
Since its launch in 2002 SimplySwitch has established partnerships with newspapers owned by Guardian Newspapers, Telegraph Group and News International. The News International partnership was agreed in March with a duration of two years.
Rival service Uswitch was bought in March by US publishing and TV group EW Scripps for £210m. Uswitch's 2006 revenue forecast at the time was in the range of £23m to £26m.
SimplySwitch is expected to deliver revenues of £6.5m over the year to September 30.
Associated's £22m acquisition includes £16.5m in cash with the rest payable as a three-year earn out.
It is the latest in a series of internet purchases by Associated, including car dealing site Carsource.co.uk, dating business Allegran, and recruitment websites Productionbase.co.uk and Retailcareers.co.uk.
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