Ratan Tata, chairman emeritus of India's Tata conglomerate, has now bought stake in online taxi-hailing firm Ola, his 10th investment in the last one year

Ratan Tata, chairman emeritus of India's Tata conglomerate, has now bought stake in online taxi-hailing firm Ola, marking his 10th investment in the last one year

Tata, a respected business leader who was the chairman of salt-to-software Tata Sons for more than two decades, has previously invested in start-ups ranging from online retailer Snapdeal to Chinese phone maker Xiaomi.

Tata, who retired as the head of over $100-billion conglomerate in December 2012 and currently serves as chairman

emeritus of Tata Sons, has emerged as a major venture capital investor since his retirement.

He has also made personal investments in online companies like Urban Ladder, Bluestone and Cardekho.com. He has also invested in mobile commerce firm Paytm and wind energy start-up Altaeros Energies.

Ola did not disclose financial details of the investment, but said Tata had taken a stake in his individual capacity.

"Tata’s strong inclination towards transportation as a segment and philosophy of creating widespread social impact through business creates a strong connection to this investment," the company said in a statement.

"Bhavish Aggarwal, CEO and Co-founder, Ola said, "It is our honor to have Ratan Tata onboard as an investor. This is a huge endorsement from one of the most respected business leaders of our times and reflects Ola’s commitment towards the future of mobility in India. We look forward to learning from Tata’s experience that will help us build a world class organization from India.”

In most cases, analysts say Tata's investments have not been big, but are considered valuable for startups because of the validation and mentorship these endorsements bring.

Ola, which competes with Uber in India, is the country's biggest online cab service.

Backed by Japan's Softbank, Ola bought TaxiForSure in March for $200 million in one of India's biggest e-commerce deals as the company plans to see off its domestic rivals and the emerging challenge of fast-growing US-based rival Uber.