Onyx Software has agreed to be acquired by privately held M2M Holdings for $92 million in cash, or $4.80 a share, ending uncertainty about future ownership of the Bellevue company.

Battery Ventures and Thoma Cressey Equity Partners, two leading private equity firms that jointly own M2M Holdings, said the deal, announced Tuesday, would help them move into the customer-relationship management-software space where Onyx operates.

Onyx would become a division of M2M's enterprise-software company, Made2Manage Systems.

Onyx headquarters would remain in Bellevue, but the fate of its 250 employees is subject to negotiations between the company and M2M over the next 60 to 90 days, Onyx Chief Executive Janice P. Anderson said. She said she did not know if she would stay on as CEO.

If approved by shareholders, the deal is expected to close by the end of September.

Anderson said the deal is the best decision for shareholders, customers, partners and employees. "This is a very strong vote of confidence for Onyx," she said.

More details about the transaction will be in a proxy statement Onyx plans to file with the Securities and Exchange Commission within two weeks, she said.

Onyx directors and officers representing 17.6 percent of the outstanding shares have agreed to the acquisition, the company said.

"This acquisition is the ideal way for Onyx to pursue its vision as a leading supplier of enterprise-caliber CRM solutions to mid and large enterprise services-sector customers," Dave Tabors, general partner of Battery Ventures, said in a statement. "We take a long-term perspective on Onyx's growth."

Onyx had received unsolicited offers from CDC Corp. earlier this year. It faced some pressure to move on the offers after one of its largest investors urged its board to negotiate a merger with CDC.

Loeb Partners of New York, an institutional investor that owns 9.8 percent of the company's shares, had questioned whether the Onyx management was working in the best interests of shareholders.

Onyx rejected CDC's initial offer, which valued Onyx at $50 million. Later, CDC, which is based in Hong Kong and operates the China.com portal, raised the bid to $4.57 a share, or about $80 million, in cash.

On April 7, Onyx said it had hired investment banker Piper Jaffray as financial adviser to assist in evaluating CDC's offer and any other strategic opportunities.

Onyx shares closed up 51 cents Tuesday to $4.68.

Kristi Heim: 206-464-2718 or kheim@seattletimes.com