Giant public pension funds like CalPERS, the California public employees fund, frequently become major stockholders in public corporations, and can use that power and influence to make changes to corporate structures. We haven’t seen a ton of activism from funds like this in recent years. But that could be changing. Witness this upcoming meeting between CalPERS and BP:

Anger at BP PLC’s handling of the Gulf oil spill is prompting one of its largest U.S. shareholders to call for changes on the company’s board.

The California Public Employees’ Retirement System, the biggest U.S. public pension fund, is conferring with BP officials next Wednesday amid criticism from some institutional investors that the board’s response to the spill has been too passive.

A person familiar with the situation said Calpers, which held 60.6 million BP shares as of June 30, is concerned about the “quality and competence of the board” and will urge changes in its makeup. The person described directors’ response to the spill, the worst in U.S. history, as “disastrous.” A BP spokesman declined to comment.

CalPERS holds 60 million shares, and isn’t really compelled to do so. They could drop them at any time. Corporations take notice when a shareholder that big seeks changes.

Shareholder revolts have become one of the more interesting activism opportunities in recent years. Union and public pension funds have used this wedge to make changes in corporate structures. While the financial reform bill will not give much power to individual investors to effect corporate compensation on board membership, giant investors like CalPERS will get even more power.

And if anyone deserves the pressure, it’s BP, which has not only failed on the level of environmental disaster and a lack of workplace safety, but has failed financially with this spill, seeing their corporate net worth plummet (which actually hurts CalPERS a great deal, in the midst of all sorts of calls in California for a public pension overhaul). CEO Tony Hayward or Chairman Carl-Henric “the small people” Svanberg could be in CalPERS’ sights.

Keep an eye on this.