No. Because the idea itself is too poorly defined and naive interpretations are often bad for shareholders in practice
If the legal obligation to maximize profit for shareholders existed we would have to develop a good definition of how is is to be measured. Alas there isn't even a unique way to summarize a stream of known cash payments over time into a single current value (the net present value calculation yields different results for different discount rates). The standard way of thinking about quoted company values which claims to resolve the problem of which discount rate to choose (the capital asset pricing model) has serious problems despite its wide acceptance (well summarized by wikipedia).
Many of the issues come down to a judgement call about making an costly investment now for higher profits in the future or just giving the cash to shareholders instead. This is a hard matter of judgement and coping with uncertainty in the future.
The Shareholder Value movement has been influential in promoting the idea that cashflow to shareholders should be the focus of senior management in quoted companies. The movement has led to some beneficial changes in business practice, but has also led many leaders to become overly obsessed with their share prices. As John Kay (a british economist and commentator) has pointed out:
Managers who focus closely on the stock price, whether by inclination or because they have incentives to do so, will often fail to serve the best interests even of their stockholders.
In another of his regular columns in the Financial Times he describes his own journey with the idea of shareholder value:
In my academic life, I taught the standard concepts of modern economic theory, based on efficient markets populated by maximising agents. Yet, as I saw more of successful businesses, I understood that they didn’t maximise anything. Such businesses were complex political organisms: they contained and were influenced by diverse individuals and groups with diverse goals, and the effective manager was someone who could mediate between these conflicting forces. If these companies talked about shareholder value – and increasingly they did – it was an instance of Franklin’s Gambit, a legitimising rhetoric rather than a real guide to action.
And the more shareholder value became a guide to action, the worse the outcome. On the board of the Halifax Building Society, I voted in 1995 for its conversion to a “plc”. We would allow the company to pursue the goal of maximising its value untrammelled by outmoded concepts of mutuality: in barely a decade, almost every last penny of that value was destroyed. In 1996, as my thoughts on this began to form, I went to the CBI annual conference and described how ICI, for decades Britain’s leading industrial company, had recently transformed its mission statement from “the responsible application of chemistry” to “creating value for shareholders”. The company’s share price peaked a few months later, to begin a remorseless decline that would lead to its disappearance as an independent company.
...These unanticipated results reflected the profit-seeking paradox, well described in James Collins and Jerry Porras’s fine book Built to Last: the most profitable companies were not the most profit-oriented.
As he summarizes:
the idea that good decisions are the product of orderly processes – is more alive than ever in public affairs.
...There is not, and never will be, such a science. Our objectives are typically imprecise, multifaceted and change as we progress towards them – and properly so. Our decisions depend on the responses of others, and on what we anticipate these responses will be. The world is complex and imperfectly known, and this will remain true however much we analyse it.
And this summary explains why the idea of "maximizing" profit is not a sensible objective in itself: the world is too complex and no formula can reduce it to a meaningful value.
A recent Washington Post blog includes some useful references and commentary. For example, the blog argues:
this supposed imperative to “maximize” a company’s share price has no foundation in history or in law. Nor is there any empirical evidence that it makes the economy or the society better off. What began in the 1970s and ’80s as a useful corrective to self-satisfied managerial mediocrity has become a corrupting, self-interested dogma peddled by finance professors, money managers and over-compensated corporate executives.
There are no statutes that put the shareholder at the top of the corporate priority list. In most states, corporations can be formed for any lawful purpose. Cornell University law professor Lynn Stout has been looking for years for a corporate charter that even mentions maximizing profits or share price. She hasn’t found one.
Nor does the law require, as many believe, that executives and directors owe a special fiduciary duty to shareholders. The fiduciary duty, in fact, is owed simply to the corporation, which is owned by no one, just as you and I are owned by no one — we are all “persons” in the eyes of the law. Shareholders, however, have a contractual claim to the “residual value” of the corporation once all its other obligations have been satisfied — and even then directors are given wide latitude to make whatever use of that residual value they choose, as long they’re not stealing it for themselves.
This provides a relatively concise summary of the case in the USA.