Citigroup ( C) has become the latest company to jump aboard the bandwagon to have corporations treat stock options as an expense.

The nation's biggest financial services firm said Wednesday it would begin expensing all stock options to management, employees and corporate directors in January. The firm estimates that by expensing options, it will reduce next year's earnings by 3 cents a share.

In recent weeks, a number of other companies have said they would start expensing options. Among them are Bank One ( ONE) and Coca-Cola ( KO).

But technology companies, which have been some of the biggest issuers of stock options, have been reluctant to join the fold. TSC took a look at this issue earlier this week.

The debate over whether companies should treat stock options as expense has picked up steam this year in the aftermath of several big corporate scandals. Critics say that the generous distribution of stock options in the 1990s provided an incentive for some corporate chieftains to play fast and loose with a company's books, in order to boost the stock price.

Citigroup also announced Wednesday that the bank's Chief Executive Office Sanford Weill and Chief Financial Officer Todd Thomson personally certified the bank's financial statements. The Securities and Exchange Commission has given the nation's 900 biggest companies until Aug. 14 to comply with a new measure that requires corporate executives to officially sign-off on a company's books.

Citigroup announced the two moves in a letter from Weill to all of the bank's employees.

In the letter, Weill also announced another policy change that seems intended to defuse some of the criticism it has gotten over its dealing with Enron -- the now bankrupt-energy trader. Weill says the bank is committing itself to "greater transparency in the disclosure of structured finance transactions."

Specifically, Weill says Citigroup will go forward with a structured financing deal only if a "company aggress to publicly disclose its impact to investors."

Citigroup and J.P Morgan Chase ( JPM) have come under fire in recent weeks for structuring deals for Enron that enable it to record some $8 billion in financing as trading liabilities rather than as loan obligations.

Several U.S. senators say the banks aided Enron in its deception by permitting Enron to make its debt-load appear much small than it really was.