Zendesk Inc shareholders have approved a $10.2 billion planned acquisition of the software maker by a group of private equity firms led by Hellman & Friedman and Permira, the company said on Monday.

The company in June agreed to be taken private in a deal that would be see investors receive $77.50 per share in cash after persistent pressure from activist investor Jana Partners.

The firm said that the deal would close in the fourth quarter of the year.

Proxy firm Institutional Shareholder Services (ISS) backed the deal and warned that there would be "significant downside risk" if Zendesk shareholders failed to approve it.

Light Street Capital Management which manages funds that own more than 2% of Zendesk said in August that it would vote against deal and proposed that it remain a standalone public company and find a new top boss.

Earlier this month, Zendesk said that macroeconomic conditions and business momentum have continued to weaken since the go-private deal announcement in late-June from the consortium.

  - Reuters