Last week Lehman Brothers went bust after the US Government refused to bail the 105 year-old institution out of its financial woes, resulting in the loss of jobs for 26,000 staff worldwide and 5,000 in the UK.
Microscope understands that Morse was the bank's preferred supplier of UNIX boxes while Computacenter provided PCs and Intel-based servers - both of whom will now not be paid.
"Lehman Brothers can't pay staff so it certainty can't [afford] to pay suppliers," said Mike Norris, Computacenter chief executive.
"We will lose some money and we have lost a customer but it will not knock us off course," he added.
In the UK, Lehman accounted for around 1% of group revenues at Computacenter but the firms did not work together elsewhere.
Morse which also counts the newly acquired HBOS among its largest clients refused to comment.