Kevin Johnson, president of Microsoft's Platforms and Services Division, just told financial analysts here in Redmond that the company is acquiring AdECN, an online ad exchange. There's no official word yet. Here's what he said:

"Today, we are acquiring AdECN, a company that launched an exchange within the last year that has 37 members, ad networks. The exchange concept is similar to Nasdaq, which serves as the hub for financial brokerages. The Nasdaq enables all parties to come together and have access through a neutral party to a larger pool of supply and demand for their clients. In the ad business, the ad exchange does a similar thing. It provides liquidity -- liquidity for publishers, liquidity for advertisers. And so with this AdECN acquisition, it complements the work we've done with adCenter. It extends the work that aQuantive brings. And it now enables us to move forward with all of the core components that we need to enable this ad platform."

He didn't disclose financial terms. AdECN lists an address in Carpinteria, Calif. More details to come. Yahoo announced in April that it was acquiring the Right Media online ad exchange.

Update: Here's the news release announcing the deal. It's expected to be completed by the end of this calendar year. Microsoft isn't disclosing financial terms, but it's saying that the deal won't have a significant impact on its financial expectations for the year. AdECN has 30 employees, and the company says they'll remain at the current headquarters in California.