The takeover of DW Technology Services will see 25 staff join Amor along with a string of clients including Asco Group, RBG and Gulf Offshore.
More than half of Amor's revenues come from the energy sector and the acquisition is seen as key to its previously stated aim of doubling turnover to 60m by 2012.
The firm, which is headquartered near Glasgow airport with offices in Edinburgh, Aberdeen, Coventry and Houston, was created in May 2009 following the acquisition of the Scottish IT services operations of French company Sword Group.
Since the private-equity-backed buyout, more than 70 staff have been hired, taking the group-wide headcount to 400-plus. In its first year of trading the enlarged group generated turnover of about 30m.
No figure was disclosed yesterday for the DW acquisition other than it being a "seven-figure" deal.
The Aberdeen firm has an annual turnover of 1.8m and a "20-year track record in the energy sector". Its co-owners Brian Docherty and Kevin Wright will join Amor's management team.
John Innes, Amor's chief executive, said: "This is a major step forward for us as we continue to expand globally.
"DW Technology Services customers will continue to work with the same people as before but will have access to the extended specialist expertise we can offer, while our customers will greatly benefit from enhanced global reach and knowledge."