The founders of Softcat, senior members of the management team, and certain current and former staff will sell shares worth about 32.5% of the company's issued share capital.
The offer price will be 240p per share, leaving the company with a market capitalisation of £472.3mln.
Softcat is expected to list on the market on November 18.
It also said it had appointed Vin Murria to its board of directors as an independent non-executive director.
Softcat chief executive Martin Hellawell said: "The successful pricing of our initial public offering on the London Stock Exchange reflects the very positive response we have received from institutional investors as we have shared our equity story in recent weeks.
"We are delighted with the outcome of the IPO process thus far and now look forward to fully focusing on the running and future development of our business."