In the latest consolidation move to hit the customer relationship management software space,

Onyx Software

( ONXS) has made an unsolicited offer to buy competitor

Pivotal

(PVTL) - Get Report

for a higher price tag than another outstanding bid.

In a letter Wednesday to the Pivotal board of directors, Onyx offered 0.475 shares for each share of Pivotal. Based on the $4.73 closing price of Onyx shares Tuesday, the offer prices Pivotal at $2.25 per share, or about $59 million.

The Onyx offer represents a 28% premium over Pivotal's closing price Tuesday and a 26% premium over the $1.78-per-share offer from venture capital firm Oak Investment Partners, announced last month.

Under that deal, Oak Investment Partners is planning to merge Pivotal with

Talisma

, a privately held vendor of Web-based customer service solutions, and to become the controlling shareholder in the combined business.

Shares of Pivotal soared 24 cents, or 13.6%, to $2 in trading that was more than eight times average volume. Shares of Onyx declined 34 cents, or 7.2%, to $4.39 in recent trading.

Pivotal shareholders are scheduled to vote on the Talisma merger Nov. 18. The Pivotal board will meet to consider the Onyx offer Wednesday or Thursday morning, said company spokesperson Leslie Castellani.

Both Onyx and Pivotal sell customer relationship management software to the middle market, businesses with sales of $100 million to $3 billion, an area that has been attracting more attention from enterprise players such as

Siebel Systems

( SEBL),

SAP

(SAP) - Get Report

,

Oracle

(ORCL) - Get Report

and

PeopleSoft

(PSFT)

.