Business software maker Salesforce.com on Tuesday launched a slimmed-down version of its customer-management services that existing customers will be able to access for free using high-end mobile phones.

The company that pioneered software as a service -- managing customers' information and data remotely on a pay-as-you-go basis -- said it could reach 1 million users with its new Mobile Lite service.

Salesforce already has clocked up 70,000 downloads of its Apple iPhone version in seven months by customers on its more expensive, all-inclusive packages.

Mobile Lite will be available to customers using Research in Motion's BlackBerry smartphones and phones running on Microsoft's Windows software as well as the iPhone, Salesforce said ahead of a company event in London on Tuesday.

The plan is to make it free. There is no plan to change it, Salesforce Chief Marketing Officer Kendall Collins told Reuters in a telephone interview.

Collins said he hoped customers using the free service would be tempted to upgrade to more expensive packages that include more mobile functions.

Mobile Lite allows customers, typically corporate salespeople, to access some of their company accounts and data and update them in real time while on the road.

We don't have a forecast for what's going to happen, Collins said when asked how many people Salesforce expected for the new service. It's going to really accelerate adoption. We think that the value of upgrading is going to sell itself.

Salesforce's offering is an example of so-called cloud computing, where customers connect via the Internet to software and data held for them at remote centers -- a model that is rapidly gaining momentum, partly due to economic conditions.

The model -- used by Google, Amazon and Microsoft for some of their business -- allows users to pay for software as they use it.

The traditional way of selling business software, practiced by Oracle and SAP, for example, involves companies buying expensive licenses and paying regular maintenance fees.

Technology research firm Gartner estimates the cloud-computing market, including Web advertising, will be worth $56 billion this year. Software as a service, the area in which Salesforce operates, is forecast to be worth $6.5 billion.

Salesforce, which expects to make sales of about $1.3 billion this fiscal year, said on Tuesday it was approaching 10,000 customers in Europe this quarter, an increase of about 70 percent from a year earlier.

Globally, Salesforce has more than 55,000 customers, including Allianz, Veolia Environmental Services and COLT Telecom, and more than 1.5 million individual subscribers at the companies who are its customers.

We think cloud computing is the right answer for right now, Collins said. Nobody is immune to the current economic environment, but we think we have a more resilient model than the traditional software model.

Salesforce's sales grew 44 percent last year and it made an operating margin of 6 percent. That compares with 19 percent revenue growth and an operating margin of 28.2 percent at SAP, the world's biggest maker of business software.

(Reporting by Georgina Prodhan; editing by Karen Foster)