Philip Kaltenbacher, chairman of the Port Authority of New York & New Jersey, wants to step aside as chairman but remain active as a commissioner because of pressing business needs, a port authority spokesman said Friday.

Mr. Kaltenbacher was named chairman from September 1985 until April 1990. But he was reappointed to the board in 1988 by then New Jersey Gov. Thomas Kean to a term as a commissioner that runs until 1994, according to Lloyd Schwalb, port authority spokesman.The board of commissioners will vote for all top positions before meeting publicly Thursday, when the holders of the post of chairman and other positions will be announced, Mr. Schwalb said.

Mr. Kaltenbacher said he requested the change in position because his company, the Seton Co., had experienced explosive growth and he wanted to devote more time to it.

"My tenure as chairman only strengthened my conviction that the port authority's contribution to the prosperity and well-being of the New York-New Jersey region is unsurpassed in the public sector," he said.

The bi-state agency manages a budget of almost $3 billion to run the New York metropolitan area's three major airports, two tunnels, four bridges and the PATH system.

According to Friday editions of the Star-Ledger of Newark, Richard C. Leone, port authority commissioner, is the choice of New Jersey Gov. James A. Florio to replace Mr. Kaltenbacher.

The paper said ranking officials in the Florio administration made the comments about Mr. Leone, 49, director of the 20th Century Fund in New York, a non-profit think tank. Mr. Leone is the only Democrat among New Jersey's six port authority commissioners.

Traditionally, the governor of New Jersey selects the authority chairman and the governor of New York choses the executive director. Stephen Berger, appointed by Gov. Mario Cuomo, is expected to be renamed executive director, the newspaper said.