UK-based Synstar, which has 1,500 customers, provides business continuity, disaster recovery, data management and network support services.
Companies running Synstar services include British Gas, Alliance & Leicester, Laura Ashley, the Royal Navy and Volkswagen.
Alan MacNeela, vice-president at Gartner Research, said HP users could benefit from Synstar's multi-supplier maintenance capabilities and its expertise in business continuity.
He added that Synstar customers should review their contracts to see if charges for services are likely to change if the acquisition goes through.
Synstar's customers, many of which are on long-term contracts, would get access to HP's services and products, said Synstar chief executive Steve Vaughan.
Vaughan said Synstar users would benefit from HP's experience in network consulting and application development - two areas that Synstar does not cover.
"We will be part of a larger organisation and have access to HP services and products, although we will retain supplier independence," he said.
Vaughan said Synstar could offer users a competitive price and had a track record in retaining customers for long periods.
In recent years Synstar has focused on mid-sized companies and government agencies, providing a range of managed services. Customers include the Defence Communication Services Agency. Synstar also provides managed services to large IT suppliers such as CSC, ITNet and Fujitsu.