Mumbai, July 28 -- The private businesses of Tata Sons envisioned to take the conglomerate to its next stage of growth sank deeper into losses in FY26, led by aviation, digital commerce, electronics assembling and battery manufacturing. Overall, losses at Tata Sons' 16 privately held businesses nearly doubled in FY26, rising to Rs.27,854 crore from Rs.15,311 crore in FY25, the Tata Sons annual report published on Monday showed. In the annual report, Tata Sons chairman Chandrasekaran compared the ongoing large investments to Tatas' earlier endeavours like the Indian Institute of Science, steelmaking, software services, and fundamental research. "Each of these bets looked audacious, even imprudent, at the time they were made. Each took decades to prove itself. And each, in hindsight, turned out to be exactly what the nation needed," he wrote in his letter to shareholders. "Losses in a diversified business group should be evaluated through the prism of the business lifecycle rather than in isolation," said Monish G. Chatrath, managing partner at MGC Global Risk Advisory, a risk consulting firm. Businesses in aviation, digital platforms, advanced manufacturing, and semiconductor ecosystems often require significant upfront investment and longer gestation periods before they achieve sustainable profitability, he said. "From a risk management perspective, the critical question is not whether losses arise during an investment phase, but whether they are accompanied by disciplined capital allocation, effective execution and measurable progress against clearly defined strategic milestones," he said. Air India remained the loss-leader in FY26. Its losses more than doubling to Rs.22,238 crore in a forgettable year where the carrier endured one of India's worst aviation disasters in recent history, and later bore the brunt of a surge in fuel costs as the Gulf war broke out. The airline's revenue declined by nearly a tenth to Rs.71,870 crore. "This year, Air India faced three external headwinds. Air space closures; West Asia conflict-driven fuel price hikes and foreign exchange fluctuations; and the crash of AI171 made it the most challenging year for Air India," Chandrasekaran wrote. Tata Digital, which houses the e-commerce application Tata Neu, continued to be the second biggest loss-maker, losing Rs.4,974 crore during the year with revenues of Rs.35,990 crore. Tata Electronics, the group's foray into smartphone assembly and semiconductor manufacturing, was the group's highest grossing private business in FY26, surpassing Air India. The company's revenue doubled year-on-year to Rs.1.3 trillion. However, the iPhone contract manufacturer also reported a deeper loss at Rs.1,611 crore compared to Rs.70 crore lost in the previous year. Lastly, Agratas, which is making two giga factories for battery manufacturing, one each in India and the UK, reported a loss of Rs.1,101 crore compared to Rs.741 crore. The business is yet to start commercial operations. Tata Sons invested Rs.1,465 crore in the company during FY26. The other dozen unlisted companies of Tata Sons made a cumulative profit of Rs.2,070 crore compared to Rs.969 crore in the previous year....