The investment will be made using the Eredene Group's existing cash reserves.
OSL, a privately owned Hyderabad-based company, which was founded in 1995, is profitable and dividend paying. It generated revenue of £26.4m, net profits of £5.2m and reported net assets of £27.4m in the year ended 31 March 2009.
OSL owns and manages a fleet of 82 vessels, comprising 59 tugs, 5 dredgers, 5 barges, 5 mooring boats and 8 pilot launches. It services 18 ports across India and also has three joint ventures in India with the Port of Singapore Authority (Marine). The OSL Group also has a joint venture operation in Oman.
OSL is the market leader in the Indian ports operations and marine services industry and provides the full range of support services to incoming and departing ships, such as pilotage, anchoring and berthing, and also undertakes dredging contracts.
Alastair King, founder and Chief Executive of Eredene, said: "The investment in OSL is a good match for Eredene as it will complement Eredene's existing portfolio of port services investments. We have a specialist ports team in India. Port services is one of the key areas where we have developed strong local partnerships. We see Indian ports and related port services as a continuing strong growth story."
The World Bank's International Finance Corporation (IFC) is an investor in OSL having first provided project financing for the OSL Group in 2003 and directly investing in preference shares in OSL in June 2009.
Eredene is buying the stake from Swiss Technology Venture Capital Fund Private Ltd, which is nearing the end of its fund life.