Online cab aggregator Uber Technologies is reported to have raised $1 billion in a fresh round of funding in which global technology giant Microsoft and Indian media firm Times Internet, among other investors, participated. 

The latest round of funding values the San Francisco-headquartered taxi aggregator at $51 billion, the Wall Street Journal reported, citing sources close to the development.

The investment also takes the overall funding in Uber – regarded as the world's second most valuable start-up –  to over $5 billion, the report said.

But a Bloomberg report, citing sources familiar with the matter, said that Microsoft has just finalised to invest nearly $100 million in Uber, valuing the company at $50 billion.

"We filed to authorise this new funding more than two months ago," Kristin Carvell, a spokeswoman for Uber, said in an email.

"We aren't commenting on additional speculation," she said.

In March, Uber had reportedly said that it would get a funding of "well under" Rs 100 crore ($16 million) from Times Internet. 

Times Internet is a subsidiary of Bennett Coleman & Co, which publishes The Times of India and The Economic Times.

Google Inc and Chinese Alibaba Group have already invested in Uber, which currently has operations in 57 countries.

Uber had said on Thursday that it was planning to invest $1 billion (Rs 6,400 crore) towards expanding its operations in India, its second largest market after the US.

The company has come out with aggressive plans for India in the past two months.

Earlier in July, the company had said that it would invest about Rs 317 crore over the coming five years to build its largest international office in Hyderabad.