Skype is opening its instant messaging technologies to developers in the face of renewed competition in the market from Google.

The company claims to "instantly be creating the largest open instant messaging platform in the world" by encouraging developers to integrate its technology into their website or applications.

The announcement comes one day after Google expanded its Web search engine and produced a new instant messaging service complete with free voice calls - Skype's exact territory.

As part of its program to help build new types of Web-based communication services, Skype is opening up its SkypeNet and SkypeWeb APIs. Although the two-year-old company has been offering presence and IM services for some time, it is best known for its core VoIP.

"We've always been about openness on the Net," said Skype co-founder Janus Friis. "Now we're taking this openness one step further."

Friis said the move to open its APIs wasn't prompted by Google's decision to enter the market, but rather as a part of a strategy to make it easier for companies, organisations and individuals to connect to the Skype platform and use the Web-based services.

Skype says it has more than 51 million registered users for its free services, and more than two million using its paid services.