MELLON BANK (EAST) (Philadelphia) - Betty Sue Peabody was named president and chief operating officer.

She was executive vice president, retail banking, at First City Bancorporation of Houston, Texas.MERRILL LYNCH CAPITAL MARKETS (New York) - Phillip W. Peloquin, managing director-municipal markets, will return to New York from Los Angeles to assume greater responsibilities in municipal markets' public finance group.

He will manage a group which will focus on national resource recovery investment banking and advisory services.

Samuel B. Corliss Jr., managing director-municipal markets, was promoted to manager of the group's western region, replacing Mr. Peloquin.

NORWEST CORP. (Minneapolis) - Sara J. Grady was named vice president, human resources development. She was director of training and development of this diversified financial services organization.