Fifteen years ago, it would have been unthinkable, and maybe even impossible.

But there it was in last year's proxy statement for Aetna Life and Casualty Co. -- the marriage announcement of Barbara Hackman Franklin, 47, and Wallace Barnes, 61.

The announcement, buried in the section called "Certain Transactions and Relationships," said that "Mr. Barnes, who became a director of Aetna Life & Casualty in 1971, and Miss Franklin, who became a director of Aetna Life & Casualty in 1979, were married in November 1986."

The point is not so much that they are living happily ever after, but that a boardroom match could be made at all. Also, fellow board members barely blinked an eye at the news, said Franklin.

"Ten years ago, I'm not sure people would have stood for this," said Franklin, president and chief executive of Franklin Associates, a management consulting firm, who serves on six boards of major corporations.

In slow but steady increments, women have been tapped to help decide corporate governance issues and share in the pay and perks of directorships -- posts that almost always used to go to men. Some 395 women held 576 directorships last year at 439 of the top 1,000 companies, according to Catalyst, a consulting firm on business and women's issues.

Ten years ago, only 18 percent of America's Fortune 1,000 even thought about having a woman on the board, according to Catalyst. Only 204 women held board positions.

Furthermore, those women who were sitting shoulder-to-shoulder with the pinstripe suits in boardrooms often were chosen more for what they didn't do than for what they could do.

"Up until about seven years ago, the chief executive officer who was looking for a woman board member was looking for a woman who was discreet and well-mannered. Someone who kept her shoes on and her hair combed," said Felice N. Schwartz, president of Catalyst. "Today they want a woman with business in her bones who can make a contribution from day one."

The National Women's Economic Alliance Foundation, which will honor 10 of America's female corporate directors for their accomplishments at a dinner here tonight, reported that 405 women currently serve on corporate boards, representing 45 percent of the nations' top 1,000 corporations.

Korn/Ferry International, a senior management search firm, reported a slight decline in the number of women holding board seats last year, probably because of seats lost through mergers and acquisitions.

This year's Korn/Ferry study of directors, based on a preliminary response of 235 companies, shows that the proportion of companies that have at least one woman on the board has increased to 52 percent. The final report will be published in February.

"The best thing I can say is that it has changed from the exotic to the routine," said Anne L. Armstrong, who serves on the boards of four companies. "I went on in 1975 and we were rarities."

But it continues to be a lonely job for a female director at the 457 companies that have women on the board. Usually, a woman sits alone, though the Alliance survey found that 116 corporations have more than one female director.

The biggest number of female directors was found in the financial, manufacturing and retail sectors, according to that survey.

Overall, women probably hold fewer than 5 percent of the directorships available at the top 1,000 companies. They are even more underrepresented as inside directors for their own companies, experts estimate.

"They are generally on the periphery of business, not the mainstream," said John H. Bryan Jr., chairman and chief executive of Sara Lee Corp., which has two women on its board. "But they make a difference in changing the attitudes of companies."

Bryan said he is concerned that the small breakthroughs that have been made in the boardroom by women will overshadow the real progress that has yet to be made -- into the ranks of top management.

"We have to have a major catchup in women in management to increase their numbers at the board level," said Bryan.

"That can best be done by advancing women to higher management levels. It would be easy to fool oneself and think we have made more progress than we have," he said.

Ascending to the top ranks of management, which has been all but impossible save for a handful of women, is crucial because companies consider the model board member to be "president or chairman, retired or sitting for a company equal in size or larger than we are," said Bryan.

Companies that are filling vacant seats with women are getting pickier. "Board directorships are becoming more important and fewer slots are allocated to women," said Jerry Jasinowski, executive vice president of the National Association of Manufacturers. "The 'ladies slot' just doesn't hold anymore."

Increasingly, women are going onto boards from functional positions within companies. Though Schwartz estimates that the pool of women positioned to go onto boards probably numbers only about 350, there are other factors working in the favor of women.

One of those is that companies are having a difficult time recruiting the typical director, who is male, because of the impact of shareholder suits and legal actions against boards. Also, Korn/Ferry reported that an increasing number of prospective directors turned down the job primarily because it took too much of their time.

Patricia Harrison, president of the National Women's Economic Alliance, said those problems increase female possibilities. "For many women, it's the feeling that this is an opportunity and 'I will take the risk,' " she said.