Profits of Southern Railway in the first quarter this year will be lower than in the same period of 1976 becuase of lost revenues and expenses associated with bitter winter weather, company president L. Stanley Crane said yesterday.

In an interview, the railroad's new chief executive since Feb. 11 said first-quarter earnings will be somewhat under a year ago," when Southern posted profits of $22 million ($1.45 a share) on revenues of $250 million.

Crane emphasized that Southern management still expects 1977 "as a whole to be an excellent, good year." He also said that his company had not suffered as great a drain on profits as operations in the Midwest and Northeast, where the winter weather has been most severe.

For example, Chessie System chairman Hays T. Watkins sent a letter to his company's stockholders this week saying that first-quarter profits would be "extremely disappointing," with freight carloadings down substantially. He also expressed optimism about the full year.

Crane, who began his railroad career at the Southern in 1937 as a laboratory assistant, succeeded W. Graham Claytor Jr. as chief executive three weeks ago when Claytor became Secretary of the Navy.

Although Crane hasn't yet moved to Claytor's old office, the new chief executive has devoted a good deal of his working hours in recent weeks explaning to financial anaylists, railroad customers and others his determination that there will be no radical changes at one or the country's most successful business enterprises.

"Southern moves bu a process of evolution rather than revolution," Crane said yesterday. But the new chief executive did become radicalized when he saw the state of Claytor's former office, including peeling paint on windows and sills. As part of his goal of "improving the property," the office is being fixed up a bit, Crane quipped.

The company's overall commitment is to "constant, steady growth in our marketplace," which includes most of the southeastern U.S., Crane said.

In the future, that marketplace could expand through a combination with another rail company. Crane said he expects a long-predicted consolidation of railroads to take place over coming decades, resulting in eight or nine major national or regional lines.

But Southern can "go it alone for an extended period of time," based on expectations that the South's economy will continue to grow over the next two decades, he added. Southern will study any merger proposal but will agree to a consolidation only if the end result will mean increased profit-ability, he added.

Shippers have a stake in rail mergers because "they get better service if a single railroad handles (freight) from origin to destination" so long as competition exists, Crane said.

He did not rule out a merger with such Northeast and Midwest lines as the Norfolk & Midwest lines as the Norfolk & Western or Chessie System if it was "worthwhile" and to the benefit of Southern. One factor that could lead to talks on such a North-South rail merger is the expected growth of coal use in this country, particularly in the South, which now consumes more coal than it produces.

Although Crane did not discuss such development specifically, he left no doubt that he thinks railraoding is a growth industry. Of the dozen largest railroads, all but Consolidated Rail Corp. (which replaced Northeast bankrupts) are profitable and paying dividends.

Crane said that once a national energy policy is established, the railroads should receive another boost because future shortages of petroleum will dictate shipping more freight on rails and less on trucks.

The Southern chief forecast that supplies of petroleum ultimately will be controlled by industry or government, forcing changes in patterns of consumption and hurting independent and nonregulated truckers now taking business away from railroads and interstate common carrier trucking firms.

"America is no longer the land of milk and honey and plenty," and the federal government will have to re-channel its direct and indirect subsidies to forms of transportation that comptte with more energy-efficient railroads, he stated.

On other subjects, Crane said:

. There is "not much" potential for increasing use of passenger trains outside dense metropolitan corridors. Buses are most efficient for long-haul service, he added.

. Southern favors establishment of transportation companies that could engage in both trucking and inland waterway service.

. The government should subsidize a major demonstration project of electrification along a freight route of 300 miles or more to provide evidence about potential savings.