After 157 years as an elite private partnership steeped in Old World secrecy and intrigue, investment bank Lazard went public in May 2005 on the New York Stock Exchange. Alas, old habits die hard.

We submit as evidence this late breaking news release from Lazard, which waited until after U.S. markets closed Tuesday to reveal it would announce fourth-quarter results Wednesday. That translates to roughly 16 hours notice for analysts, investors and reporters who follow the activities of this expanding merger advisor.

Not that anybody is breaking the rules here, but it makes you wonder why a company held by small and big investors alike waited so long.  Certainly famed Lazard chief Bruce Wasserstein wants his efforts to get plenty of attention, right?

According to this glowing profile  in Portfolio magazine,  ”Bid ‘em up Bruce” has made a full recovery from a wealthy but somewhat marginalized banker to become an even richer, vindicated genius. That’s because he runs a firm that makes most of its money by providing advice to companies and governments and by managing money: no exotic CDOs, no ill-advised bets on mortgages, no hung LBO loans.

Analysts expect Lazard fourth-quarter earnings to soar, capping off a strong 2007  with a second half much stronger than the first. Company executives in recent months assured that the outlook for strategic M&A, or deals not involving leveraged buyout firms, should remain healthy.

Yet Lazard’s share price tells a more cautious story. Despite its lack of exposure to the credit crunch and its recent success serving as consigliere to sovereign wealth funds, Lazard stock is down 15 percent in the past month and down 31 percent over three months. The market seems to be taking the position that if corporate chiefs choose to stay on the sidelines, a firm depending on M&A will suffer.

Which brings us to Wednesday’s surprise earnings results. Investors can only hope that Lazard is more forthcoming about the outlook for its business than it was about the date of their quarterly confessional.