Companies Chemical Banking plans to reduce its work force by 9 percent in an effort to cut costs.

A currency trader at Chemical Banking who bet on the peso's strength lost his company $70 million.

Stocks fell again yesterday, partly in reaction to a 63 percent dividend reduction by Chemical Banking, the nation's sixth-largest banking company.

Companies Chemical Banking's earnings rose 28.7 percent, to $151.7 million.

The idea of a merger between Chemical Banking and Manufacturers Hanover had been talked about for years before a deal was finally announced last week.

Over all, Chemical Banking said it earned $357 million for the second quarter, down 6.3 percent from $381 million a year ago.

Citicorp, Chemical Banking and Chase Manhattan all reported unexpectedly robust quarterly profits.

Even some analysts who do like Citicorp see better value in the other money-center banks, particularly Chase Manhattan and Chemical Banking.

And Chemical Banking advanced 1/4, to 45 3/8, after its chairman said earnings would be greater than analysts' forecasts.

If bank mergers were a race, Chemical Banking would be a lap behind.