Software-as-a-service (SaaS) platform Zendesk has been acquired by a group led by global investment firms Permira and Hellman & Friedman in a $10.2 billion all-cash deal.

Under the terms of this agreement, Zendesk shareholders will receive $77.50 per share. The offer represents a premium of approximately 34 per cent over Zendesk's closing stock price on June 23.

Zendesk will become a privately held company upon completion of the transaction.

"This is the start of a new chapter for Zendesk with partners that are aligned with the strength of our agile products and talented team, and are committed to providing the resources and expertise to continue our growth trajectory," said Mikkel Svane, Founder, Chairman and CEO, Zendesk.

Zendesk started the customer experience revolution in 2007 by enabling any business around the world to take their customer service online.

Today, Zendesk connects more than 100,000 brands with hundreds of millions of customers over telephony, chat, email, messaging, social channels, communities, review sites and help centres.

The company employs more than 6,000 people across the world.

"We believe Zendesk is uniquely positioned to enable meaningful interactions and deliver compelling business outcomes across any channel," said Ryan Lanpher, a Partner at Permira.

"We deeply believe in the company's growth opportunity as it continues to help businesses across the world delight their customers," added Tarim Wasim, a Partner at Hellman & Friedman.

In addition to Hellman & Friedman and Permira, the investor group includes a wholly-owned subsidiary of the Abu Dhabi Investment Authority (ADIA), and GIC.

The transaction is expected to close in the fourth quarter of this year and is subject to customary closing conditions.