The Resolution Trust Corp. announced that the following actions were taken Friday:
* Arrowhead Pacific Federal Savings Bank of San Bernardino was closed and insured depositors will be paid off. Arrowhead Pacific had deposits of about $89.8 million in 6,500 deposit accounts, virtually all of which are within the $100,000 federal insurance limit.
* The insured deposits of Security Federal Savings Assn. of Garden Grove were transferred to ITT Federal Bank of Irvine. The failed S&L's only office will reopen today as an ITT Federal office. Security Federal has assets of $68 million and liabilities of $71.5 million.
* The RTC board approved paying off insured depositors in Los Angeles-based American Interstate Savings Assn. because no acceptable bids to buy the thrift were received. American Interstate, with assets of about $21.6 million and deposits of about $20.5 million, was closed Friday.
* The sale of Sierra Savings & Loan Assn. to Sun Savings Bank, both of Beverly Hills, was approved. Sun Savings, a newly chartered federal savings bank, is assuming all deposits and secured liabilities of Sierra, which total about $36.7 million. The former Sierra Savings branches will reopen today.
* A conservator was appointed for Peninsula Savings & Loan Assn. of San Francisco by the Office of Thrift Supervision. Peninsula, which has about $67.4 million in assets and $47.7 million in deposits, will maintain normal business hours.