Job training is a booming business -- increasing numbers of workers are pursuing more sophisticated and high-tech positions. For-profit educators such as Apollo (NASDAQ:APOL) and Career Education (NASDAQ:CECO) are growing in popularity due to their tailored curriculums, designed to assist students in meeting this challenge. It's not boom times for every postsecondary educator, though. Just ask Corinthian Colleges (NASDAQ:COCO).

Fellow Fool Rich Smith recently noted analysts' projections that Corinthian would earn $0.08 per diluted share in the first quarter of fiscal 2006, and the company met those expectations. Corinthian's earnings are a 50% decline from last year's $0.16; struggling sales are part of the problem, but the company's weakening profitability is the primary culprit.

Operating margins were at the wrong end of a principal's paddle, declining a staggering 6.3 percentage points to 5% vs. 11.3% last year. The squeeze on profits stems from several factors, including increased educational services outlays, general and administrative costs, and marketing and admissions expenses.

Corinthian's sales fared a little better but were far from impressive. The company's top line grew by 5.3%; however, even excluding the effects of Hurricane Katrina, its student count declined 4.2%. Single-digit revenue growth can be temporarily stomached, but a declining population is worrisome. It's also a major concern for Corinthian's leadership; in the earnings release, CEO Jack Massimino emphasized the company's continued efforts to "increase student enrollment growth and operating margin."

In a quarterly report filled with unpleasant news, perhaps the one ray of sunshine is Corinthian's still-healthy balance sheet. Management seems to have confidence in the company's future prospects; it plans to spend part of its $115.1 million in cash to buy back $70 million in stock.

Share buyback programs can help increase shareholder value, but they're not reason enough to go shopping for Corinthian's stock. Prospective investors will want to continue monitoring the company to see if it indeed has a successful strategy to reverse its shrinking margins and student population.

Psst! Crib off our notes on Corinthian:

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Fool contributor Jeremy MacNealy does not own shares of any companies mentioned.