Guitar Center Inc., beating its own estimates, reported fourth quarter sales increased 18.5 percent to $468.9 million, and comparable store sales rose 10 percent for the same period. Net sales from the company’s stores increased 18.4 percent to $362.8 million from $306.3 million in the fourth quarter last year. Westlake Village-based Guitar Center attributed the increase to guitar sales and, in particular, guitar and bass packages. Company-wide net sales for the year increased 18.7 percent to $1.5 billion, compared with $1.3 billion for 2003. As a result of the company’s recent performance, Guitar Center officials increased their earnings guidance for the fourth quarter of 2004. The company said it now expects earnings per share in the range of $0.89 to $0.92, versus previous guidance in the range of $0.80 to $0.88. The company will release its full financial results for the fourth quarter and full year on February 9. Guitar Center presently operates 136 Guitar Center stores, 19 family music stores under the moniker American Music and a direct response retail arm, Musician’s Friend Inc.