Ronald Reagan may have chosen Malcolm Baldrige to head the Commerce Department for a number of reasons.

Baldrige is a successful businessman, having taken Scovill Inc., from a 160-year-old manufacturer of brass buttons and other milled products in the early 1960s and turning it into a diversified producer of housing fixtures and appliances, increasing its sales five-fold.

He and Reagan also share a common past-time -- riding. Baldrige, who worked on a Nebraska cattle ranch as a teenager, is a professional calf-roper in rodeo competition, keeping in practice in the roping arena on his 140-acre farm in rustic Woodbridge, Conn. Those interests appealed to Reagan, associates say.

In the end, though, it was probably Baldrige's ties to George Bush, Reagan's running mate, that pushed him into the Cabinet picture, according to Baldrige's friends.

A leader in Connecticut's Republican Party and a delegate at the GOP national conventions in 1968, 1972 and 1976, Baldrige was chairman of Bush's primary campaign in Connecticut this year. Like Bush, Baldrige is a graduate of Yale University and is active in its fund-raising. He and Bush even look a little alike -- both are thin six-footers.

Like the other Reagan Cabinet choices presented at a press conference yesterday, Baldrige didn't drop any clear clues as to his approach to the Commerce position.

"Inasmuch as I haven't found the front door to the Department of Commerce yet, I think I'd better let that one wait," he said yesterday, when asked about his intentions for the Commerce Department. His business career may provide some clues to the question, however.

He was raised in Omaha, son of an attorney who served one term in Congress, from 1930 to 1932. After service in the U.S. Army in World War II, he joined the Eastern Co. in Naugatuck, Conn., as a foundry foreman and became its president in 1960. He joined Scovill in 1962 as executive vice president and became president a year later.

One labor official who dealt with Baldrige said he turned Scovill from a company with a combative antagonism toward unions into one with good labor relations. "I think from Balrige's day on, the longest strike was about four hours," said this official.

The company and the United Auto Workers, which represented Scovill's foundry and manufacturing workers, established a counseling program to prepare workers for retirement that later became a model for a Canadian government plan.

His remarks yesterday suggest he will have an open door to labor as well as business. "We are going to need government, labor and management all working together" to solve the country's problems with productivity and inflation, he said.

When Baldrige took over at Scovill, the company's business was still predominantly brass-product manufacturing. It had made brass buttons since its founding in 1802, supplying them for military uniforms for every American military conflict from the War of 1812 on.

Recognizing the threat of competition from lower-priced imports and the risks of a highly cyclical business, Baldrige pushed Scovill out of the brass business into the fast-growing market for home furnishings and appliances.

"Before, it hadn't really grown substantially in the last 20 or 30 years," Baldrige told an interviewer several years ago. Success came from "sticking your neck out if you're sure you're right and getting lucky." Scovill's sales rose from $160 million in 1962 to $941 million last year.

Baldrige, 58, received salary and bonuses totaling $343,431 last year and owns 137,030 shares of Scovill stock.

Like other New England manufacturers, Scovill moved major parts of its business to southern states in the 1960s, one observer noted. Unlike many, however, Scovill didn't abandon its home base of Waterbury, maintaining a company headquarters there.

Baldrige was among the business leaders who became involved in trying to solve the racial tensions that hit U.S. cities in the 1960s, associates say. He supported programs to build nonprofit, low-income housing and establish job programs for minority workers in the Waterbury area. After the murder of the Rev. Martin Luther King Jr. in 1968, Baldrige flew Waterbury black leaders to the funeral in his private plane.

In a recent interview, he endorsed the Republican campaign proposal to establish "free-enterprise" zones in depressed urban centers, giving companies tax incentives to establish new manufacturing plants there. The best assistance a ghetto youth can receive is a job with a good manufacturing company, he said.