The Federal Home Loan Mortgage Corp. has named Kenneth J. Thygerson as its new president and chief executive officer effective Aug. 16.

The FHLMC, also known as Freddie Mac, makes a secondary market in conventional mortgages and sells mortgage-backed securities to investors to free up funds for additional lending by banks and savings and loan associations.

Thygerson, 37, was chief economist for the U.S. League of Savings Associations for 11 years until April 1981. He is currently executive vice president of Western Federal Savings and Loan Association of Colorado.

Recently he served on the President's Commission on Housing, which proposed long-range solutions for solving the residential crisis. Thygerson said he considers his new position "a great opportunity to implement many of the kinds of things we talked about, such as further increasing the role of secondary-market institutions in making housing competitive for dollars in the investment market."

He replaces Philip Brinkerhoff, 39, who has been Freddie Mac's president since 1977. Brinkerhoff will become president of First Charter Financial Corp., and its subsidiary, American Savings and Loan Association of Beverly Hills, Calif.

Chartered in 1970, Freddie Mac has pumped more than $41 billion into the mortgage market.