MOUNTAIN VIEW, California: Google is intensifying efforts to persuade firms to use its free online business software applications by teaming with a publisher of software for tracking sales calls.

The search titan's Gmail service together with its word processor and spreadsheet programs will be available to Salesforce's 40,000+ customers immediately, while customer support for Google's applications will launch later this year.

San Francisco-headquartered Salesforce has been collaborating with Google for some years to make it easier for customers to share information between  Google's applications and its own.

Despite declarations to the contrary, the search leader has been steadily ratcheting-up competition with Microsoft and its Office suite programs.

Salesforce founder and ceo Marc Benioff believes "cloud computing" is a potential threat to bigger software makers like Microsoft and Oracle which make most of their money from selling individual licenses and charging additional maintenance fees.

This latest announcement has reignited speculation that Google might be about to acquire Salesforce, estimated to be worth around $7 billion (€4.49bn; £3.5bn). But both companies remain zip-lipped about any such plans.

Data sourced from Wall Street Journal Online; additional content by WARC staff