Financial Corp. of America, the nation's largest savings and loan association, yesterday announced its 1985 strategy, which includes a plan to dramatically decrease the size of the troubled California thrift.

The company, which suffered a loss of about $7 billion in deposits after being forced to restate its second-quarter earnings by the Securities and Exchange Commission, said yesterday it wants to shrink from about $30 billion in assets to $24.5 billion. It will have trouble achieving this restructuring, however, if interest rates rise too much during the year, because the company would have difficulty selling its portfolio of fixed-rate assets profitably.

The restructuring is part of the company's plan to change the mix of its assets from fixed to floating rate, and to increase the proportion of deposits from individuals, as opposed to institutions.

"We realize we have set ambitious objectives for this year, which can be met if a reasonably favorable interest rate climate prevails in 1985," said William J. Popejoy, chairman and chief executive officer.

The company also said it wants to meet a 4 percent net worth requirement by the end of the year. The net worth requirement for most S&Ls is 3 percent, but Financial Corp.'s required level was raised to 4 percent by government regulators when they approved the company's acquisition of American Savings and Loan in 1983. Net worth requirement is the amount, determined by a formula, of reserves an institution must keep on hand in relation to its total size.

"We feel the achievement of the 4 percent net worth requirement is an essential goal in rebuilding the strength and vitality of this institution," Popejoy said. "We believe this plan also provides the necessary tools to accomplish the association's overall goal for increasing American Savings' Financial Corp.'s principal subsidiary financial strength and reducing its exposure to interest rate risk."

The company's 1985 plan has been approved by the Federal Home Loan Bank Board, which is supervising the S&L closely. The bank board has agreed not to take any supervisory action against the company during 1985 based solely on the company's inability to meet its 4 percent net worth requirement, Financial Corp. said.

Popejoy also said the company's fourth-quarter results will not be released until an independent real estate task force has completed a study of Financial Corp.'s loan portfolio. That study is expected to be completed in late February.

Analysts are anxiously awaiting the results of the study because they are concerned about the unusually high level of problem real estate loans in the company's portfolio.

Other objectives for 1985 announced yesterday include:

Meeting or exceeding regulatory liquidity requirements on a monthly basis; restraining the growth of total troubled assets; reducing the one-year gap between interest-rate-sensitive assets and liabilities; maintaining the stability of savings deposit flows; continuing to reduce the premium paid to attract deposits; and reducing general and administrative expenses by at least $35 million from the 1984 level.