IT services vendor CSC plans to separate its $4.1 billion US public sector business to form a new company.

The move is the latest step in a restructuring that began three years ago and will see CSC's mission divided between US government clients and all others.

The US public sector business, expected to be operational by October, will target federal, state and defence customers and employ 14,000 people. That business generated $4.1 billion in revenue last year.

CSC's remaining 51,000 employees will focus on commercial customers, and public sector organisations outside the US. That business recorded revenue of $8.1 billion last year.

The split will happen at about the same time as that of another ageing tech giant, HP, which is also breaking in two. CSC was founded in 1959, while HP was founded 20 years earlier.

HP is cleaving its PC and printing divisions away from its enterprise hardware and service businesses, an effort to stimulate growth and make its shareholders happier.

While the two CSC businesses are very different in size, they're about evenly split when it comes to profitability. In the fiscal year just ended, CSC's public sector work in North America earned it operating income of $591 million, versus $567 million for the rest of its business.

CSC said it's making the split because government clients are looking to work with companies that have specific experience in government work. The new businesses will be called CSC Global Commercial and CSC US Public Sector.

In late 2014, CSC said it would pay $190 million to settle a case brought by the US Securities and Exchange Commission over four-year-old charges that it violated US antifraud, reporting, and books-and-records laws. At issue was the way it accounted for work in Australia, Denmark and the UK.