Adobe Systems Inc. agreed to acquire software maker Marketo Inc. for $4.75 billion, bolstering its marketing tools in a bid to compete against Inc. and Oracle Corp. in a fast-growing business.

The deal, which would be Adobe’s largest ever, is expected to close during the fourth quarter of fiscal 2018, the San Jose, California-based company said in a statement.

Adobe, the maker of image-editing tool Photoshop, has sought to develop a software suite that includes advertising, analytics and e-commerce programs. Adobe purchased Magento Commerce for $1.7 billion in June to enter the market for e-commerce. Marketo, owned by Vista Equity Partners LLC, provides one of the last pieces of that puzzle.

“Our ability to get a greater share of the wallet we think is enhanced with this acquisition,” Adobe Chief Executive Officer Shantanu Narayen said on a conference call.

Marketo sells marketing software that companies use to identify and reach new customers through email, text messages, social media and other channels. It also offers analytical services, and is particularly strong in helping businesses market to other businesses. Vista bought San Mateo, California-based Marketo in 2016 for $1.8 billion.

“To participate in the business-to-business marketing-automation market, Adobe needed the functionality that Marketo brings,” Lori Wizdo, an analyst at Forrester Research Inc., wrote in an email.

Adobe will gain almost 5,000 customers through the acquisition, and Marketo Chief Executive Officer Steve Lucas will join Adobe’s senior leadership, the companies said.