(Sharecast News) - Pensions administration specialist Equiniti said it had extended its contract with the Cabinet Office and buying out the government department's stake in a joint venture for £8m.The contract to administer the civil service pension MyCSP will now run until the end of 2021, Equiniti said.MyCSP is a 51/24/25% joint venture partnership between Equiniti, the Cabinet Office and an employee benefit trust.The employee benefit trust will retain its 25% stake in MyCSP. Equiniti said it expected the deal to be accretive to earnings."MyCSP has made a significant investment in technology and services for public sector pensions administration, and has the experience and scale to operate the largest and most complex of schemes," the company said.The transaction is expected to complete later on Thursday.