Delta Air Lines Inc. (DAL) is in talks to buy a minority stake in Japan Airlines Corp. (9205.TO), a move that would fill a key gap in the U.S. carrier's global alliance strategy, according to a person familiar with the situation.

The talks started a few weeks ago and could take several months to complete, said the person.

Delta, the world's largest airline by revenue, lacks a Japanese partner in its SkyTeam alliance, and is concerned about being squeezed when international flights start next year from Tokyo's Haneda airport. Delta operates a hub at the city's Narita airport.

JAL is developing a new medium-term restructuring plan, and has been seeking government and private-sector finance for fleet and route changes and to bolster its pension fund.

While Delta and JAL are both losing money amid the global slump in air travel, a minority investment of just a few hundred million dollars could help cement a tie and lure JAL from the rival Oneworld alliance headed by British Airways PLC (BAY.LN) and the American Airlines unit of AMR Corp. (AMR). All Nippon Airways Corp. (9202.TO), Japan's second-largest carrier after JAL, is a member of the third global alliance, Star.

Japanese media reported Delta will buy a stake worth several tens of billions of yen in the Japanese airline, making it JAL's biggest shareholder. The Kyodo news agency reported Delta's stake will come in the form of a new share issue reserved for the U.S. carrier

Some analysts were more skeptical, given the scale of the turnaround needed at JAL. "Delta and JAL could form a code-sharing alliance...(but) an investment of only Y10 billion or so would be just a drop in a bucket for JAL," said one Tokyo-based analyst.

A Delta spokeswoman declined comment on reports of a tie-up with JAL, first reported by Japanese media. A spokesman at JAL said nothing has been decided. A Oneworld spokesman also declined comment on the reports, but said JAL was "an important and valued partner" in the Asia-Pacific region.

JAL expects to show a net loss of Y63 billion in its fiscal year to March 2010, after losing Y63.2 billion in its last business year.

The Delta-JAL talks come as U.S. and Japanese negotiators conclude a three-day meeting aimed at securing an "open skies" deal to liberalize air travel between the countries.

-By Doug Cameron and Hiroyuki Kachi, Dow Jones Newswires; 813-6895-7550; hiroyuki.kachi@dowjones.com

(Yuzo Yamaguchi in Tokyo contributed to this article.)