A Florida-based nutrition company, agreement to acquire H. G. Parks, Inc., of Baltimore, one of the only two black-owned corporations in the country that is publicly traded.

Under terms of a preliminary agreement, Norin will pay about $5.1 million in cash, or $10 a share, for outstanding shares in Parks, which currently manufactures and distributes pork sausages and other specialty meat products along the Eastern Seaboard from Virginia to Massachusetts.

The price of Parks stock, traded over-the-counter, has increased sharply in recent weeks.

Parks, founded in 1951 by chairman Henry G. Parks Jr., completed its most successful year in the 12 months ended last Oct. 2 Sales rose to $14.7 million from $13.1 million the previous year and profits increased to $460,631 (86 cents a share) compared with $333,052 (62 cents).

Black Enterprise magazine has ranked the parts company as the seventh larges black owned and/or managed firm in the nation for the past two years.

Norin Corp. became a public financial services company in 1972 when a private real estate firm merged with several life insurance companies.When real estate depression set in during recent years, Norin management decided to dispose of mortgage banking, real estate and insurance businesses and to concentrate on nutrition, Norin president Morton D. Weiner said in an interview yesterday.

About a year ago, Norin acquired a 74 per cent interest in Maple Leaf Mills Ltd., of Toronto, Canada's biggest flour milling firm. Sales for 1976 were $540 million, Weiner said.

Norris Grain Co., a private firm controlled by Norin chairman Bruce A. Norris, owns 52 per cent of Norin Corp. stock.

Parks went public in 1969 with an offering of common stock at $8 a share. The price fell in subsequent years to nearly $1 a share before rebounding in recent months. In fiscal 1976, Parks traded in a range of $2.50 to $4 bid per share.

Since last October, however, the price of Park shares has been increasing steadily. Parks opened the year at $4.125 a share bid, rose to $5.50 by early March, $6.25 a week ago and $7.25 Tuesday. Yesterday, Parks closed at $8 bid, $9.50 asked, on a volume of 1,980 shares.

Parks did not return a reporter's telephone calls yesterday but informed sources said he would remain with the company for a number of years. One business associate said the 60-year-old Parks "wanted to get as good a deal as possible for stockholders before he stepped down."

About 56 per cent of Parks stock is owned by Parks and William L. Adams, a friend and prominent Baltimore businessman.