* Guitar Center Inc. said third-quarter profit rose 33% to $5.8 million, or 23 cents a share, compared with $4.4 million, or 19 cents, a year earlier. Revenue rose 17% to $300.1 million. Same-store sales rose 7%.
* Discount Internet access company United Online Inc.'s earnings more than quintupled in its fiscal first quarter. Westlake Village-based United Online reported profit of $8.9 million, or 19 cents a share, compared with $1.5 million, or 3 cents, a year earlier. Revenue rose 53%.