* NSE index down 0.19 pct, BSE index 0.17 pct lower
* Tata Group firms rise after Mistry's announcement
* ICICI Bank, SBI among top losers
By Arnab Paul
Dec 20 (Reuters) - Indian shares fell slightly on Tuesday in thin trade, heading for their fifth straight session of declines, dragged down by financial stocks.
Global sentiment was mixed as U.S. Federal Reserve Chair Janet Yellen gave an upbeat view of the labour market while deadly incidents in Germany and Turkey weighed on markets.
MSCI's broadest index of Asia-Pacific shares outside Japan was down 0.05 percent.
Back home, the broader NSE index was down 0.19 percent at 8,089 as of 0555 GMT, while the benchmark BSE index was 0.17 percent lower at 26,329.19.
"Investors are cautious about a Russian retaliation and this increase in geo-political tension could see most of them remain on the sidelines," said Vinod Nair, head of research at Geojit BNP Paribas Securities.
Analysts say the withdrawal of funds by foreign institutional investors and lacklustre market activity at the year-end could see the indexes trade in a small range throughout the month.
Financial stocks were the biggest laggards with ICICI Bank shedding as much as 1.5 percent and State Bank of India declining up to 2 percent.
However, shares of most Tata group companies edged higher after Cyrus Mistry, the ousted chairman of holding company Tata Sons, announced his decision to quit from the boards of group companies late on Monday.
Tata Consultancy Services Ltd and Tata Power Ltd rose as much as 1.7 percent and 2.8 percent, respectively.
"I expect Tata Group companies to react positively to the news as most fund houses have been backing Ratan Tata from the start of the controversy," says Mugilan K, deputy manager of research at Cholamandalam Securities. (Reporting by Arnab Paul in Bengaluru; Editing by Subhranshu Sahu)