Ariba this week will unveil upgrades to eight of its spending management software products.
Its focus is on helping companies better manage spending on services such as legal help, marketing and travel.
The new releases, which are being announced at Ariba's annual user conference, will be available in June.
Martin Boyd, Ariba's director of marketing, said the products are aimed at services that typically account for up to half of all expenditures within companies.
Such services "are a big chunk of spending and are growing faster than other expenses", Boyd said. But, he added, "a lot of companies have no idea what they're spending on services."
Ariba's upgraded applications can manage spending in 16 categories, including travel, marketing, utilities, insurance and health benefits, Boyd said. The software can also be used to track staffing costs, such as expenses for temporary workers and the use of recruiters.
Consumer electronics retailer Best Buy last week announced that it is expanding a deployment of Ariba's products and said it wants to begin using the software to automate the management of contracted services.
Best Buy, which has been an Ariba customer since late 2000, currently has about 80,000 employees using the supplier's purchasing and travel expense management tools.
The new roll-out by Ariba includes upgrades of the purchasing, contracting and invoicing software, plus revised versions of tools such as the company's sourcing and spending analysis products.
"The 'wow factor' of this announcement is that Ariba is putting more functionality around services," said Christa Degnan, an analyst at Aberdeen Group. "If a company has done any e-procurement, this is the next level."
The services components are "relatively unique" to Ariba, Degnan said, citing PeopleSoft as its closest competitor.
Ariba was one of the pioneers of online procurement software but has struggled since the business-to-business bubble burst. Two weeks ago, the company reported a $51.6m (£32m) net loss on revenue of $59.3m for its second quarter, which ended 31 March.