Rumors Send First Interstate Stock Down : Banking: An announcement of a major restructuring is believed to be imminent.

First Interstate Bancorp’s stock dropped again Wednesday in active trading on expectations that the Los Angeles bank will disclose today or Friday details of a restructuring expected to involve a large charge-off and significant job cuts.

Rumors of big job cuts, circulating for weeks among employees, built this week in anticipation of a First Interstate directors meeting today. First Interstate declined comment.

Banking analysts estimate that the bank will take a charge to earnings of $80 million to $200 million. That would involve anywhere from a few hundred job cuts to more than 1,000, depending on how widespread a revamping First Interstate decides to make.

“Cutting staff has to be a significant part of it. It will probably be across the board,” said Ronald I. Mandle, banking analyst with the New York investment house Sanford C. Bernstein & Co.

First Interstate’s stock was off 50 cents to $30.625 in New York Stock Exchange trading, with more than 448,000 shares trading hands. That followed a drop Tuesday of $1 per share.

First Interstate, parent of First Interstate Bank of California, has been going through a lengthy restructuring that began in late 1989.

The bank signaled in Securities and Exchange Commission documents filed in mid-August that it was on the verge of taking another major step in its revamping. It has yet to disclose details, saying only that the changes will have a “material” impact on its earnings.

Like other California banks, First Interstate has seen its problems loans increase. It has been one of the more cautious California banks in its statements about the state’s economic prospects, especially the softening real estate market.

First Interstate, the nation’s ninth-largest banking company with $51 billion in assets, for some time has said that the real estate market is unpredictable, indicating that problem loans are likely to increase.