Sir Martin Sorrell tells us WPP wanted to buy Datalogix but didn't want to stump up the $1 billion Oracle reportedly paid for it

The world's largest advertising agency holding company WPP was interested in buying data broker company Datalogix, but wasn't prepared to stump up the reported $1.2 billion price tag Oracle eventually paid for it, WPP chief executive Sir Martin Sorrell told Business Insider.

Speaking to Business Insider at The World Economic Forum's Annual Meeting in Davos, Sorrell said around three years ago himself and the chairman of WPP's media investment management group Irwin Gotlieb sat down and identified the five or six companies they wanted to buy.

Since then, WPP has made some big investments and acquisitions - such as investing in independent ad tech company AppNexus, taking a stake in TV measurement company Rentrak, and buying a stake worth around $300 million in online measurement firm comScore.

Sorrell said: "The only one in that list two and a half to three years on - and we've invested a lot of money - that we didn't make an investment in or buy was Datalogix, which we were sad about but we just couldn't compete with Oracle."

He added that he wouldn't rule out further acquisitions and investments in the ad tech space.

Noting that public ad tech companies have suffered on the public markets in the last year, Sorrell while he doesn't primarily look at the public markets, private valuations get priced on them - which could be beneficial from WPP's perspective.

Any correction on the public market will have an implication on private market expectations.

"I think it's a bit like Brazil. A couple of our competitors went crazy in Brazil to try to catch up for lost time. India was the same. They made some dreadful mistakes on valuation, overpaid for the companies, the companies collapsed or had real problems and you see that in the results if you get the country-by-country results. And that's been good because it's reduced the tendency for people to overpay - although it still does happen. The fact the markets have come off a bit has probably helped."