SEOUL, Feb 17 (Reuters) - South Korea has expanded its scrutiny of pay schemes into insurance and credit card firms after the country's president called on companies with strong profits to help ease the cost-of-living burden for vulnerable people.

The Financial Supervisory Service (FSS) is checking with major insurance and credit card companies whether their profit-sharing bonus payments were excessive relative to profits, a media department official said on Friday, without elaborating.

South Korea's top insurance companies and credit card companies include Samsung Life Insurance, Samsung Fire & Marine Insurance and Shinhancard.

Yonhap news agency reported some of the major insurance companies recently paid their employees as much as half their annual wage as a performance bonus.

The regulator's move extends a campaign of President Yoon Suk-yeol that previously targeted banks and telecoms service providers. Yoon asked companies in those two sectors this week to share more of their profits with people who needed help.

Yoon's government, in office for less than a year, also wants banks and telecom companies to share profits with vulnerable people by lowering debt-service costs or mobile phone service fees.

Reaction in the shares of insurance companies and parents of credit card companies was muted. Investors were more focused on declines in global equity prices on worries about further U.S. rate hikes. (Reporting by Choonsik Yoo; Editing by Bradley Perrett and Sonali Paul)