Even the sun was shining today in this typically drizzly corner of the country, yet another sign that the American Telephone & Telegraph Co. is indeed enjoying blessed times.

America's largest utility firm announced at its annual shareholders' meeting here the best first-quarter earnings in the company's 102-year history. Profits for the quarter were $1.96 per share, up 8 cents over the corresponding quarter a year ago.

Clearly buoyed by the strong performance. Charles L. Brown, AT&T's new chairman, played down widespread speculation about a recession either in the communications business or in the national econony. "The future is not so gloomy as some of our economists prdict," he told reporters.

Highlighting the reasons for his optimism, Brown pointed to a near-record growth in demand for phones (Ma Bell now has more than 133 million in service) and toa surge in long-distance calling. AT&T is currently handling 11.5 percent more long-distance calls than it was a year ago.

But Brown conceded that the months upcoming are likely to carry with them some lumps. He predicted a "dip" in the national economy either late in 1979 or early 1980, though he said it would be neither a very deep nor a very long dip.

He said, too, that 1979 would likely be "a year in which earnings improvements will be harder to come by," due both to rising costs and greater resistance among utility commissioners to rate increases.

Also clouding AT&T's horizon are several bills recently introduced in Congress to reform the 1934 Communications Act. Hearing on these bills are set to begin next week. Noting this, Brown told shareholders he viewed the months ahead as extremely critical passage" in the Brell System history.

"At risk," he said, "is our continued ability to manage the nationwidepublic-switched network." Referring to some proposals which would break up some parts of the Bell System, Brown asserted: "That network, in order to work as one must be designed and operated as one."

He warned that "abrupt changes" in AT&T's time-honoured relationships with more than 150 subsidaries "could have drastic technological and economic consequences."

Asked about the status of the Justice Department antitrust suit against AT&T, which calls for divestiture by the phone company of the Western Electric manufacturing srm and several other subsidaries, Brown said he had no reason to expect an early settlement. He added, however, that congressional action might make the case moot.

Brown said he favoured deregulation of the communications industry - something that the pending legislation would promote. Though lifting of the government's regulatory umbrella would expose AT&T to all sorts of new competitive pressures, Brown said he would welcome it. "We are not at all concerned about being able to handle ourselves in competition," he remarked.

It was partly in anticipation of such changes that AT&T moved last year to reorganize its entire management system internally along marketing lines - such as business, residence and network - instead of traditional engineering and traffic groupings.Brown defended the switch to shareholders, saying "it does not, as some people have assumed, signal a change in the historic purpose of our business,"

In keeping with its position as the U.S. company with largest number of shareholders-it a has more than 2.9 million-AT&T prepared for its 94th annual meeting in grand fashion. It rented Seattle's opera house, installing special glass booths from which shareholders could ask questions, and set up 40 exhibits in a neighboring hall featuring Bell system products and furturistic technologies. Nore than 2700 shareholders attended.

On other Bell system and related matters raised today:

William Cashell, AT&T's chief financial officer, conceded in response to a question that company earnings may be overstated due to a depreciation method used by the utility that is slower than methods used by unregulated firms. He said that AT&T may eventually have to change its method and adhere more to the norm.

Brown said he still hopes Iran will pay $37.5 million owed AT&T for communication services provided by a subsidiary. In the meantime, AT&T has sued Manufacturers Hanover Bank to put a lock on $30.2 million in Iranian funds being held by the bank in connection with the aborted contract.

On inflation, Brown said he did not believe President Carter's anti-inflation program was failing. He noted that AT&T's prices have gone up 40 percent since 1967 compared to a rise in the consumer price index of about 100 percent during the same period.

U.S. Steel Chairman Edgar Speer, in a surprise move, did not seek reelection to the AT&T board of directors. Speer underwent surgery for a "stomach ulcer" last fall and has not returned to work full time sincce. CAPTION: Picture, CHARLES BROWN . . . at AT&T annual meeting, AP