Jan 8 (Reuters) - India's equity benchmarks opened marginally lower on Thursday, amid cautious sentiment, as U.S. tariff worries and foreign fund outflows offset optimism over earnings growth.

The Nifty 50 fell 0.13% to 26,106.50, while the Sensex traded 0.22% lower at 84,778.02, as of 9:15 a.m. IST.

Fifteen of the 16 major sectors logged losses. The broader small-caps and mid-caps were flat.

The Nifty 50 index slid 0.7% in the last three sessions, and the Sensex lost 0.9%, after U.S. President Donald Trump warned of higher tariffs on Indian goods over Russian oil purchases, even as New Delhi seeks a trade deal with Washington.

The U.S. has already imposed up to 50% tariffs on Indian goods, with half of those penalties tied to New Delhi's Russian crude imports.

Meanwhile, foreign investors sold Indian shares worth 15.28 billion rupees ($169.95 million) on Wednesday, provisional data showed. They have offloaded $694 million worth of shares so far in January after record outflows in 2025.

(Reporting by Vivek Kumar M; Editing by Sumana Nandy)