US software provider Blackbaud has announced it plans to acquire Convio for roughly $312m, forming one of the largest software-as-a-service (SaaS) vendors in the market.

The two software providers have entered into a definitive merger agreement and the deal, which was supported unanimously by both boards, is expected to close in the first quarter of 2012.

Blackbaud will buy all Convio’s outstanding shares of common stock for $16 per share and will finance the deal through a combination of cash and debt.

Marc Chardon, president and CEO of Blackbaud said: “The addition of Convio will broaden Blackbaud's application portfolio, enabling the combined company to offer a comprehensive set of multi-channel supporter engagement solutions to non-profit organizations of all sizes.”

Following the acquisition Convio’s president and CEO, Gene Austin, will take a role on leadership position at Blackbaud reporting to Chardon.

Austin said that the company had previously received requests from users to integrate Convio’s fundraising solutions with Blackbaud’s CRM software, and said that: “We will now be able to meet this market demand and provide both our customer bases with access to a broad and deep application suite designed specifically for non-profit organisations.”

In October 2011 Blackbaud acquired the Austrailian peer-to-peer fundraising platform Everyday Hero. And last summer Convio acquired the UK digital strategy agency Baigent Digital, which has since become Convio UK.

Convio UK provides online marketing solutions to UK charities including Unicef, Cancer Research UK and Action for Children and plans to introduce the introduce the Convio TeamRaiser events fundraising product line to the UK market in early 2012.