Arcelor Mittal and Nippon Steel Corp. reportedly plan to double the capacity of their U.S. joint venture that produces steel for the U.S. automotive market.

The two companies, the world's two largest steel producers, currently produce automotive steel at the I/N Kote steel processing facilities, their joint venture in New Carlisle. The facilities near the border of LaPorte and Saint Joseph counties supply high-quality galvanized steel sheets to Japanese transplant automotive manufacturers in North America.

Nikkei, a Japan-based business daily, has reported that Arcelor Mittal President Lakshmi Mittal and Nippon Steel President Akio Mimura reached the agreement Sunday to double their joint venture's 500,000 ton annual capacity. The publication stated that although details of the size and structure of the investment have yet to be finalized, the agreement could mean investments in facilities and equipment topping $250 million.

"We're having a constructive dialogue and hope to continue our good relationship," said Mittal Steel USA spokesman David Allen on Tuesday in response to questions about the project. Mittal Steel USA is the U.S. division of Arcelor Mittal N.V.

The Nikkei report also says Arcelor Mittal and Nippon Steel would look at additional tie-ups in Europe and other areas. Nippon Steel currently supplies automotive steel to the local factories of Japanese automakers in Europe under partnership with Arcelor. It quotes Nippon's Mimura saying his company's relationship with Arcelor "may expand if there are benefits."

The $550 million I/N Kote electrogalvanizing line began production in September 1991 and added a hot-dip galvanizing line three months later. An adjacent facility, I/N Tek, a continuous cold-rolling mill, began commercial production the preceding year. in April 1990.

Hourly workers at I/N Kote are represented by United Steelworkers Local 9231. No one from the local could be reached for comment Tuesday.

At the time, the $1.1 billion investment in I/N Tek and I/N Kote was the largest sum ever committed to a U.S. joint venture by American and Japanese companies.