Shares of for-profit education company Apollo Group Inc. sank as it faced weaker enrollment and restructuring costs. The University of Phoenix operator has in recent years seen decreased revenue as enrollment has declined. In the third quarter, Apollo said, Phoenix degreed enrollment was 287,500, a 17 percent drop from a year earlier, and new degreed enrollment was down 24 percent. For the period, Apollo reported a profit of $80 million, or 71 cents, down from $134 million, or $1.13, a year earlier. Revenue fell 16 percent.