Two Maryland bank holding companies named new chairmen last week in boardroom actions that appeared to be fairly routine. The appointments denote a significant changing of the guard at both institutions, nonetheless, and could be precursors of further shifts in Maryland banking.

In the first instance, Alfred H. Smith, sometimes referred to as the dean of Maryland banking, resigned as chairman of Citizens Bancorp in Riverdale and its principal subsidiary, Citizens Bank of Maryland. Smith, 81, cited health-related factors as reasons for his resignation after 54 years with Citizens.

He will be succeeded by a son, Alfred H. Smith Jr., who had been vice chairman since 1980.

Only a day before the announcement of Smith's resignation, directors of First Maryland Bancorp elected Jeremiah E. Casey, a representative of Allied Irish Banks of Dublin -- the Baltimore bank company's biggest stockholder -- as chairman to succeed J. Owen Cole who retired.

The timing of changes at the helms of the two Maryland institutions is purely coincidental, of course. They are significant, nonetheless, and coming when they did, obviously intensify years of speculation about the future of the two companies.

In the case of Citizens Bancorp, the end of Alfred Smith's tenure as head of the organization could signal a radically different course, though Smith's staunchly conservative influence is likely to remain for a while.

Smith was Citizens Bancorp. His autocratic yet simple management style spearheaded Citizens' growth from that of a small rural bank to a strong and highly rated suburban institution. As an example, Bank Financial Quarterly, in its latest survey of the nation's commercial banks, gave Citizens a superior rating for its financial strength.

Citizens' approach to banking once was described by an officer of the bank as "nothing fancy, no frills, no bells and whistles. Just down-to-earth common business sense."

Alfred Smith's no-nonsense, no-frills stewardship extended even to the makeup of the holding company's board, which includes only his son and three long-time business associates. None of the company's directors other than Alfred Smith Jr. is an officer of the company.

Alfred Smith, who had been a director since 1933, was unique among his peers in the banking industry. He accepted no salary or bonuses while he was chairman, though it should be pointed out that he is direct owner of 9 percent of the company's stock, which closed yesterday at $115 a share.

The essence of Smith's banking philosophy came through in a rare interview he gave three years ago. "We make loans to people we know something about and do not try to make loans to Timbuktu," he asserted. "I can't see how you can make loans in these foreign countries if you're not an expert on them. We don't make loans outside our market area. We stay in our own back yard."

Unlike most Maryland bank companies, Citizens has ruled out interstate mergers or acquisitions, choosing instead to buy a string of smaller Maryland banks, boosting its assets to well over $1.7 billion. With 113 branch offices in the lucrative Washington and Baltimore suburbs, a portfolio of "safe" loans and a history of impressive earnings, Citizens is considered a plum for potential buyers.

An obvious question is, where does Citizens go from here? A more crucial question, however, is whether Alfred Smith Jr., the new chairman and chief executive officer, will bring a different management style and philosophy to the company. At least one observer of Maryland's banking industry believes that Citizens will stick to its basic business formula. The same observer added, however, that he anticipates that Citizens will augment its fundamental approach to banking by taking a fresh look at today's consumer needs as well as what he called a new era in banking.

That could mean a departure from the rigid stance against interstate banking. Certainly most observers expect to see the emergence of a different banking organization even if it remains independent.

At First Maryland, meanwhile, the appointment of Casey suggests that Allied Irish is preparing to assume a more active role in directing the fortunes of Maryland's second-largest bank company. Later this year, Allied Irish is expected to increase its interest in First Maryland to more than 50 percent as part of the agreement that officials of the two companies signed four years ago.

Two years ago, First Maryland announced that it was holding merger talks with an out-of-state bank holding company. It later disclosed that the talks had been terminated, but never identified the other company. First Maryland has been conspicuously quiet in the interim about its intentions amidst a wave of mergers involving Maryland bank companies.

Charles Cole (no relation to J. Owen Cole) will continue as president and chief executive officer at First Maryland, but Casey's election as chairman certainly appears to herald a new era.