Marriott Corp. yesterday reported that its net income climbed 20 percent to $167.4 million ($6.20 per share) for 1985, compared with $139.8 million ($5.18) in 1984.

Annual sales for the Bethesda-based international hotel, entertainment and food conglomerate rose 20 percent to $4.2 billion, compared with $3.5 billion the previous year.

Strong performances in Marriott's food services and lodging operations boosted annual earnings, said J. W. Marriott Jr., chairman and president of the company. Marriott said the improved results reflected a strong economy and increased travel as well as continued growth in the number of Marriott units.

"Our earnings have grown at a compound annual rate of nearly 20 percent for the last 30 years, and our return on shareholders' equity was 22 percent again in 1985," said Marriott. "The company has tripled its sales and earnings since 1979."

Earnings for the fourth quarter, ending Jan. 3, rose 24 percent to $51.8 million ($1.91), compared with $41.8 million ($1.57) during the same period the previous year. Fourth-quarter earnings were increased by 7 cents a share from net gains on three hotels sold offset by various charges primarily related to lodging and foreign operations.

*Gannett Co. Inc., the nation's largest newspaper publisher, said its 1985 earnings climbed 13 percent to $253.3 million ($3.16), compared with $223.9 million ($2.80) the previous year.

Operating revenue for the year increased 13 percent to $2.2 million, compared with $1.9 million during the previous year.

Net earnings for the fourth quarter rose 7 percent to $79.4 million (99 cents), compared with $74.5 million (93 cents) during the same period a year ago. Operating revenue jumped 9 percent to $619.5 million, compared with $570 million in the same quarter of 1984.

Gannett Chairman Allen H. Neuharth cited the "continuing progress of USA Today" as a factor in the improved earnings.

Gannett said USA Today has become the second-largest U.S. newspaper, with daily circulation rising to 1.4 million in 1985.