BALTIMORE (AP) _ Insurance giant USF&G Corp. cut its dividend twice in three months, from 73 cents to a nickle per share, plans sell secondary businesses and expects further staff cuts as it tries to deal with losses.

The moves reflected a trend among financial services to cut jobs and other costs in response to sagging returns on investments.

''The actions taken today were done to strengthen the balance sheet and take the risk out of it,'' USF&G spokeswoman Kerrie Burch-DeLuca said.

The company lost $610 million in the fourth quarter, or $7.32 per share. In 1989's fourth quarter, the company made $104 million, or $1.20 per share. Revenue for the quarter ended Dec. 31 slipped 4.1 percent to $1.17 billion from $1.22 billion a year earlier.

More than half the loss, or about $355 million, was attributed to the cost of restructuring the company's diverse investment portfolio to liquidate risky stocks, real estate and bonds.

For the year, USF&G lost $569 million, or $6.99 a share, in contrast to a profit of $119 million, or $1.24 a share, a year earlier. Revenue for the year fell 3.4 percent to $4.54 billion from $4.70 billion.

USF&G said its quarterly common stock dividend would be cut from 25 cents a share to 5 cents, effective April 30. The dividend was cut to 25 cents from 73 cents after a $15 million loss was reported in the third quarter.

The regular quarterly dividend of $1.025 on preferred stock will be maintained.

''USF&G just felt that instead of that money going toward the dividend, it would be better to keep it internal to benefit the balance sheet,'' said analyst Talbot Daley, a vice president in market analysis for Legg Mason, a Baltimore investment firm. ''That's very intelligent. I don't think there's any risk to the viability of USF&G, but it's going to be a long, slow grind out of a very negative situation.''

After the first dividend cut last November, analysts said the company hadn't earned enough money to pay its dividend since 1989.

In response to the news Wednesday, USF&G stock fell $1.75 to $8.75 in trading of New York Stock Exchange issues.

USF&G said it would discontinue its leasing, travel services and other non- core businesses and concentrate on its insurance and investment management businesses. The discontinued operations lost $108 million during the year, and the company charged $68 million against earnings in connection with the plans to discontinue them.

Buyers are being sought for those businesses, DeLuca said.

The number of employees to be let go is still being worked out. A study of the company is currently being conducted and should be completed by the end of March, she said.

The company said last month that about 900 jobs would be cut as part of a $75 million cost-cutting program that was initiated in November. The company also cut advertising and promotional spending and sold the corporate jet as part of that program.

USF&G currently employs 11,000 nationwide. The company had assets of $13.9 billion at the end of 1990. Its principal subsidiary is the United States Fidelity and Guaranty Company.