Software service provider Zendesk announced Thursday that it will acquire Momentive Global, owner of the popular SurveyMonkey platform, for nearly $4 billion in an all-stock deal.

Momentive shareholders will receive 0.225 shares of Zendesk stock for each share of Momentive stock they own, which is worth $28 per share at the time of the announcement.

This will be the largest acquisition of the technology company.

Zendesk’s stock fell 16% in post-market trading, while Momentive also rose 9% to $22.70 a share.

Momentive, formerly known as Survey Monkey, went public in September 2018 at $12 a share, and the San Mateo, California-based company changed its name to Momentive in early 2021 as it looked to expand into a portfolio of experience management services.

Zendesk, a provider of customer service software, faced challenges during the pandemic as its corporate clientele accelerated its digital transformation.

The deal is expected to be sealed in the first half of 2022, after Zendesk and Momentive have given their final approval.

Zendesk also announced that its quarterly revenue rose 32% to $347 million and expects the acquisition of Momentive to further improve its revenue plan to $3.5 billion in 2024, a year ahead of its earlier forecast.