Salesforce.com has ratcheted up its rivalry with Oracle by appointing the database giant’s former head of sales, Keith Block, who had left the firm under a cloud after conversations containing a scathing attack on its management came to light.

The two firms have increasingly come to blows, with former Oracle exec and now Salesforce chairman and chief executive, Marc Benioff, once blacklisted from the Oracle OpenWorld trade show.

“We are thrilled to welcome Keith to Salesforce.com,” said Benioff. “His exceptional track record leading sales, consulting and engineering teams makes him a powerful addition to our world-class distribution and leadership team.”

Block spent 26 years at Oracle, rising to head of US sales. But perhaps his most notable contribution there came as a result of a lawsuit between Oracle and HP, in a spat over support for Itanium.

HP published emails obtained as part of the e-discovery process in which Block dismissed Oracle’s president Mark Hurd [pdf] as making “lot’s [sic] of noise, not much results”. Block also described the hardware that Oracle had acquired as part of its $7.4bn Sun deal, as a “dog”.

Block left Oracle shortly after the comments came to light. At Salesforce, Block will lead the company’s global sales, customer support and consulting services organisations. He has also gained a seat on the company’s board of directors.

Last year, Oracle boss Larry Ellison claimed Benioff only got the idea to set up Salesforce.com after listening in on a meeting with Evan Goldberg about setting up an enterprise resource planning business on the internet. That firm went on to become NetSuite.

For his part, Benioff has often taunted his former boss for the glacial pace at which the firm has adopted cloud technology.