Craig McCallum and Brian Aiken have been taken on as part of Protégé's expansion programme.
Global Equity Partners and Go Equity also participated in the round.
The fund will focus on the Nordic region and Germany and will make investments in established industrial and services companies.
The size of the investment has not been disclosed but it's reported that the deal values Comstock at "a substantial premium" over its first round valuation.
The two companies see this as a good time to explore investment opportunities in Latin America.
This fourth round brings the total raised by the company to E389m.
The two new appointees will be based in Carlyle’s London office.
Geocapital, Apax, Advent, VCF Partners and Chase Episode 1 sign the cheques.
Viewgate Networks, a provider of Internet Protocol (IP) service measurement software has secured a $20m second round of venture capital financing.
Allianz Capital Partners, Round1’s chief executive and some private individuals have invested in this second round of financing.