Amadeus Capital Tuesday said it has invested EUR650,000 in software company Linkdex, the London-based venture capitalist's sixth investment out of The Amadeus and Angels Seed Fund.

Linkdex, which operates out of London and San Francisco, makes software which allows companies and agencies to analyse and manage the natural search results for their online businesses more efficiently.

"We map hundreds of billions of links rather than just the thousand currently available," said Linkdex Chief Executive John Straw.

"Going beyond the first 1,000 links is crucial, because there are true diamonds in the rough that can make a huge difference in any marketer's campaign – and we're the only way to find them," he adds.

Linkdex's search tool and merged Web and blog databases have created a Web map of over 1 trillion links and it provides marketing consultancy for blue-chip companies, such as Rolls Royce Group PLC (RR.LN) and Cisco Systems Inc. (CISCO).

Amadeus, which invests venture capital in growing companies as well as early stage and start-ups, has some GBP460 million under management. It has built several global companies including CSR PLC (CSR), maker of single-chip bluetooth radios for short range connections, and Solexa Ltd, a developer of next generation genetic analysis systems, which was bought by U.S. Illumina, Inc. (ILMN) in 2007.

-By Marietta Cauchi, Dow Jones Newswires; +44 207 842 9241; marietta.cauchi@dowjones.com