Japan Post is in final talks to form a capital alliance with Asocia Corp., a delivery company affiliated with the Daimaru Inc. department store chain, in a bid to strengthen its services in areas where it competes with private-sector firms, Japan Post officials said Wednesday.

It would be the public corporation's first investment in a private-sector firm -- a move likely to spark criticism from competitors. Private-sector firms see Japan Post as squeezing their business through what they say are unfair advantages as a public entity.

Japan Post is also considering investing in other firms and is expected to apply for permission to do so with the Internal Affairs and Communications Ministry later this month or early next month after working out detailed plans, including the investment ratio, the officials said.

Osaka-based Asocia is mainly involved in packaging and delivering merchandise for department stores, and providing direct-mail service for corporate customers in the Kinki region. It has more than 100 distribution centers with a capital of 34 million yen and about 850 employees.

The move comes as post offices are handling fewer mail and other items with the increasing use of e-mail.

Monday's rejection by the House of Councilors of a set of bills to privatize state-backed postal services has made it difficult for Japan Post to expand the scope of its business immediately.

But the public corporation is seeking to bolster its services in areas of parcel and direct mailing deliveries within the framework of the current law.

Japan Post was created in 2003 by taking over the three postal services of mail delivery, savings and life insurance from the government. It is allowed to invest in private businesses operating in areas closely linked to its services.