German business software giant SAP said Tuesday it was acquiring US cloud-based e-commerce firm Ariba for $4.3 billion in a move boosting its arsenal against arch-rival Oracle.

"The acquisition will combine Ariba's successful buyer-seller collaboration network with SAP's broad customer base and deep business process expertise to create new models for business-to-business collaboration in the cloud," a statement by the firms said.

"The move positions SAP in a fast-growing segment as buyers and sellers across the globe connect in new ways through the cloud."

The Ariba board of directors has unanimously approved the deal, which offers a 20 percent premium to Monday's closing price.

Headquartered in Sunnyvale, California, Ariba has approximately 2,600 employees and had $444 million in total revenue last year,

The deal highlights the move to broader data storage systems in the Internet "cloud" for business transactions.

"The cloud has profoundly changed the way people interact. The impact will be even greater as enterprises connect and collaborate in new ways with their global networks of customers and partners," said SAP co-chief executives Bill McDermott and Jim Hagemann Snabe.

"Cloud-based collaboration is redefining business network innovation, and we are catching this wave in the early stage of its evolution. The addition of Ariba will create the business network of the future, deliver immediate value to our customers and provide another solid engine for driving SAP's growth in the cloud."

The acquisition is the latest development in the fierce rivalry between SAP and California-based Oracle.

The two firms, which have battled in the past over acquisition targets, are also involved in a copyright infringement court case.