* In early stages of talks to buy minority stake -sources
* Nikkei says Nippon Life to take 20-30 pct stake (Adds background)
By Taiga Uranaka
TOKYO, Sept 27 (Reuters) - Japan's biggest private-sector life insurer, Nippon Life Insurance Co, is in talks to buy a minority stake in U.S. investment company TCW Group, sources with direct knowledge of the deal said on Wednesday.
The Nikkei business daily reported Nippon Life was in talks to take a 20 to 30 percent stake in TCW from Carlyle Group , which owns about 60 percent, adding it aimed to close the deal by year-end.
The sources said the talks were in the early stages and specifics of the deal had yet to be determined, including how big a stake Nippon Life would buy. They declined to be identified because the talks were not public.
Headquartered in Los Angeles, TCW provides products in fixed income, equities, emerging markets and alternative investments. It had $196.9 billion in assets under management as of the end of June.
Nippon Life and rival Japanese insurers have been hit by diminishing returns from investment in Japanese government bonds and other securities amid the Bank of Japan's massive stimulus measures, prompting them to seek riskier but higher-yield assets.
In an interview earlier this year, Nippon Life President Yoshinobu Tsutsui said his company was looking for acquisition opportunities for overseas asset management companies and life insurers.
Spokesmen for both Nippon Life and TCW declined to comment. Carlyle officials were not immediately available for comment. (Reporting by Taiga Uranaka; Editing by Chang-Ran Kim and Stephen Coates)