The Federal Reserve Board has given eight banking  companies permission to create a new clearing house for foreign exchange   transactions.   
The Fed, in a Dec. 4 order, said Chase Manhattan Corp., First Chicago  NBD Corp., and six Canadian banks may invest in Multinet International   Bank, a limited purpose trust company established to help them net their   foreign exchange contracts.     
  
The clearing house will limit its transactions at first to U.S. and  Canadian dollars. But the Fed said Multinet may later seek permission to   add other currencies.   
Multinet agreed to impose several safeguards. These include monitoring  the financial health of member banks and withholding payments from   institutions that default on their contracts.