With its first close planned for this summer at €50 million, the Rockley Follow-On Fund will invest in established technology companies in the UK, with a particular focus on the energy, sustainability, new media, data management and healthcare sectors. Its typical investment per deal will be between €5 million and €15 million.

The brothers also plan to launch a sister fund investing in overseas technology companies.

Andrew and Robert Rickman have taken the roles of chairman and managing partner respectively at Rockley Group, the newly formed entity that manages the fund.

Andrew is the founder and former CEO of optical components maker Bookham, and chairman of venture-backed companies in the UK, US and China, while Robert has experience as a director of listed and unlisted companies and as a fund manager.

Companies the brothers have invested in include Chinese fibre optic system specialist Shandong Micro-Sensor Photonics and UK-based Spikes Cavell, a provider of expense management software to the public sector.