Yahoo Inc. on Wednesday released a new version of its desktop-search application, adding the ability to search instant messages and contacts within Yahoo services.

The software, available in beta, was launched in January, as the Sunnyvale, Calif., portal joined rivals Google Inc. and Microsoft Corp. in trying to embed themselves in consumers'' PCs via a desktop-search engine.

The latest version from Yahoo searches instant messages sent and received from Yahoo Messenger and contacts contained in the online Yahoo Address Book.

Yahoo''s application uses X1 Technologies Inc.''s search engine to index emails, attachments, documents, music, images, videos and other content. X1 claims to scan more than 200 different file types, including Outlook email, PDF, HTML, text, ZIP, MP3 and Word, Excel and PowerPoint documents.

Google, Microsoft and Yahoo are targeting desktop search because most people looking to buy or research products on the web head to a search engine first, experts says Tying a person''s PC to a shopping and entertainment portal through a desktop-search engine is a way to lure them to that site first.

In other news, Yahoo said Tuesday that it would quadruple the storage of its free online email service to 1GB, starting in mid-April. The additional storage brings Yahoo on par with Google, which offers the same amount of storage through its GMail service, which is available in beta through invitation only.