SAN FRANCISCO, Aug 27 (Reuters) - Nutanix, which builds data infrastructures for companies, has raised $140 million in another funding round, which valued the firm at $2 billion, the firm said on Wednesday.

That price tag puts it into an elite group of venture-backed companies with valuations that until recently were largely beyond the reach of startups.

Investments came from Fidelity Investments and Wellington Management, according to a person familiar with the situation, underscoring the increasing eagerness of mutual funds to take stakes in the largest private companies well before potential initial public offerings.

Neither Fidelity nor Wellington responded to requests for comment.

Nutanix did not give details of how it came to the $2 billion figure, or what percentage of the company the $140 million represented.

"Our goal was to really build a relationship with institutional buyers," said Dheeraj Pandey, the Nutanix chief executive officer. "What results out of that is a much bigger IPO," not just because of the relationships but because the funding round gives the firm more time to grow as a private company.

Pandey said he was eyeing an IPO sometime next year, or possibly 2016, depending on market conditions.

The latest investment came a few months after an investment of $101 million from Riverwood, Khosla Ventures, and others in January.

Before the latest round, Nutanix had raised over $170 million from venture firms including Battery Ventures, Blumberg Capital, SAP Ventures, and Lightspeed Venture Partners.

Nutanix, founded in 2009, builds server and storage systems and competes with older companies like Hewlett-Packard Co , IBM and EMC Corp. Its customers include Toyota.

Fidelity and Wellington both invested in transportation service Uber's recent $1.2 billion funding round, which valued the company at more than $18 billion.

Other startups worth more than $1 billion include payments company Stripe, online home-furnishings company Wayfair and enterprise-data management company Cloudera.

(Reporting by Sarah McBride; Editing by Jeffrey Benkoe)