J.P. Morgan & Co. is acting as arranger and documentation agent with  administrative agent Chase Manhattan Corp. on a $1 billion syndicated loan   for Danbury, Conn.-based Union Carbide.   
The credit replaces an equal portion of a $1.2 billion loan placed by  the same two banks in 1994. The bank meeting for the credit was held   Thursday, according to Loan Pricing Corp.   
  
Pricing on the five-year revolver starts at 21.5 basis points above the  London interbank offered rate, with a facility fee of 11 basis points.   Commitments are due Jan. 10, Loan Pricing said.   
Separately, Standard & Poor's assigned a B-plus rating to a $60 million  revolver for Occusystems. The Dallas-based company is the largest   consolidator of medical practices focusing on occupational services. The   speculative-grade ratings reflect the company's rapid growth from a small   base and the risks of operating in a highly regulated environment.