Software maker Apttus has raised raised more money from private investors, postponing plans for an initial public share offer until next year because of the current uncertainties facing markets, including the U.S. presidential election.

Apttus said on Wednesday it has raised $88 million from investors, nudging its valuation to more than $1.3 billion. The round included new investor Gulf Islamic Investments, a financial services firm based in the United Arab Emirates, and previous investors such as the Kuwait Investment Authority.

The latest round brings Apttus, which makes cloud-based software for companies' sales operations, to $274 million in total funding.

Apttus was putting the finishing touches on its IPO filing early this year, just as the stocks of cloud computing companies took a beating. A deep sell-off in February hit the likes of Salesforce.com Inc and Workday Inc and effectively shut down IPO opportunities for many software start-ups, with the subsequent rally in share prices only adding to the uncertainty.

As a result Apttus Chief Executive Kirk Krappe said having put his company's IPO plans on hold earlier in the year he is now eyeing the first half of 2017 for the company's market debut.

'The beginning of the year was frothy, up and down,' Krappe told Reuters this week. 'There were see-saw valuations of SaaS (software-as-a-service) companies, and coupled with the elections at the end of the year, it just seemed too uncertain. And markets of course hate uncertainty.'

Other technology companies have opted for more venture funding to avoid the rocky IPO market. Cyber security company LogRhythm last month raised $50 million from private investors after postponing plans for an IPO late last year.

Although Apttus was founded in 2006, it did not raise venture capital until 2013. Apttus had been profitable, Krappe said, but three years ago decided to invest more heavily in expanding the business, and turned to private investors.

As a result, he said, Apttus investors are not pressuring him to go public just yet.

The company also announced on Wednesday a new addition to its software product - an intelligent agent, or a computer program that can perform certain tasks and speak and respond as a human would. Other examples of intelligent agents are Amazon.com Inc's Alexa and Apple Inc's Siri.

Apttus's intelligent agent is called Max, and she both speaks and responds in text to users' questions, and assists them in tasks using the software, such as generating a sales quote.

Based in San Mateo, California, Apttus has about 1,200 employees and more than 500 customers. (Reporting by Heather Somerville; Editing by Bill Rigby, Greg Mahlich)