SLM Corp., commonly known as Sallie Mae, reported a profit of $416.5 million ($2.64 per share) for the first quarter, essentially unchanged from the same period a year earlier when the company earned $422.3 million ($2.63).

Reston-based Sallie Mae originates and buys government-guaranteed and other student loans and is a leading provider of financial services to higher education. It manages $81 billion in student loans for more than 7 million borrowers.

The company has maintained that its earnings as computed under generally accepted accounting principles do not present an accurate picture of its performance. So it also computes what it calls "core cash" income, which takes a different approach to various components of its business, including the treatment of loans that it packages into securities to sell to investors.

On that basis the company earned $203.3 million ($1.28), up from $170.4 million ($1.05) in the year-earlier quarter.

Company officials said they were happy with the quarter, especially with a 22 percent increase in "preferred channel" loan originations from a year ago. Preferred-channel loans are those made by the company's owned or affiliated brands, and cost the company less to acquire. Sallie Mae is seeking to become the complete provider of many loans, from the initial commitment to disbursement to the processing of payments to, if necessary, collection of delinquencies.

Preferred-channel loans are therefore a key measure of Sallie Mae's success in gaining market share and drive earnings growth, the company said.

The $81 billion in managed student loans is up from $73 billion a year ago.

Sallie Mae officials also said that a mistake the company made in computing monthly payment amounts for some 800,000 of its borrowers cost the company about $9 million. The error caused certain borrowers to make payments that were inadequate to repay their loans in the scheduled 10-year term. The company is now notifying these borrowers that their payments will go up, but it is crediting them with interest they might have been charged because they had possession of their loan principal slightly longer than they were scheduled to.

* Danaher Corp., the District-based maker of Craftsman tools, posted first-quarter earnings of $103.1 million (65 cents per share), compared with a loss of $91 million (58 cents) a year earlier, when Danaher had expenses from an accounting change. Sales rose 19 percent, to $1.19 billion.

The company, which also makes devices for measuring voltage and fuel-tank leaks, bought at least nine businesses in the past year with combined sales of more than $1 billion.

In the recent quarter, Danaher completed the acquisitions of Gasboy International for $38.3 million, and label-equipment maker Willett International Ltd. for about $110 million.

* Cardinal Financial Corp., the parent of McLean-based Cardinal Bank, earned $366,000 (4 cents per share) in the first quarter, compared with a loss of $62,000 (1 cent) a year earlier. It was the third profitable quarter in a row after a restructuring period.

The company credited the improvement to higher interest margins, despite declining rates, which offset added costs of a new Arlington branch office and the move of its corporate headquarters to McLean in March.