The following table sets forth, for the periods indicated, the percentages which certain items of income and expense bear to our revenue for such periods.
Revenues for the year ended December 31, 2000 decreased $15.2 million, or 8.4%, to $166.6 million from $181.8 million in 1999. Revenues from our third party administration segment decreased by $23.9 million due to certain carrier partners exiting the fully insured market beginning in 1999 and the termination of our administrative and marketing agreements with SunStar Health Plan, Inc. Revenues from our PlanVista Solutions segment increased by $8.8 million due to the addition of new customers.
Agent commission expense for the year ended December 31, 2000 decreased $7.0 million, or 12.5%, to $48.9 million from $55.9 million in 1999. This decrease was realized in our third party administration segment and is consistent with the decrease in fully insured revenues for the period indicated, as described above.
Personnel expense for the year ended December 31, 2000 decreased $1.4 million, or 2.1%, to $64.1 million from $65.5 million in 1999. Personnel expense in our third party administration segment decreased $1.6 million due to a decrease in salaries and wages resulting from 147 fewer average employees as we reduced our workforce pursuant to the revenue decreases in our fully insured business. Personnel expense in our PlanVista Solutions segment increased $1.3 million as salaries and wages increased to meet the demands of increased revenues. Corporate personnel expenses decreased $1.2 million primarily due to lower salaries and wages.
General and administrative expense for the year ended December 31, 2000 decreased $6.4 million, or 16.1%, to $33.3 million from $39.7 million in 1999. Expenses in our third party administration segment decreased $7.4 million. We recorded $4.7 million in 1999 for claims asserted by four former customers (see Note 12 to the financial statements appearing elsewhere in this Form 10-K). We also realized favorable variances in office rent due to the closure of fully insured office facilities, and a commensurate decrease in costs attributed to postage and professional services. Expenses in our PlanVista Solutions segment increased $2.3 million, due to increased network fees resulting from increased revenues and the cost of imaging our records. Corporate expenses decreased $1.3 million, primarily due to decreased cost for our corporate insurance program.
Loss on impairment of intangible assets for the year ended December 31, 2000 was $80.3 million. On April 1, 2001, we entered into a definitive agreement to sell our third party administration segment and managing general underwriter business unit (see Note 16 to the financial statements appearing elsewhere in this Form 10-K). Based upon the consideration received in this agreement, our goodwill and contract rights related to the business units sold became impaired, and we recorded an $80.3 million charge.
Interest expense for the year ended December 31, 2000 increased $1.9 million to $9.6 million from $7.7 million in 1999. This increase resulted from an increased average interest rate of 373 basis points on our line of credit due to the amended terms of our credit facility (see Note 9 to the financial statements appearing elsewhere in this Form 10-K). This increase was partially offset by a reduction of $9.2 million in the average outstanding principal balance on the credit facility.
On July 5, 2000, we sold our unemployment compensation and workers' compensation units for a pretax gain of $7.3 million. On September 15, 2000, we sold our Ohio workers' compensation managed care organization unit for a pretax gain of $3.2 million, and on October 26, 2000 we sold our self-funded unit for a pretax loss of $52.5 million (see Note 4 to the Financial Statements appearing elsewhere in this Form 10-K).
The following Management's Discussion and Analysis of the financial results for the year ended December 31, 1999 compared to December 31, 1998 have been recast to reflect the revised income statement format being presented in the year ended December 31, 2000. This recast reflects that the units sold during the year ended December 31, 2000 are discontinued operations. The units sold were our unemployment compensation, workers' compensation, workers' compensation managed care organization, and self-funded units (see Note 4 to the Financial Statements appearing elsewhere in this Form 10-K).
Revenues for the year ended December 31, 1999 decreased $19.4 million, or 9.6%, to $181.8 million from $201.2 million in 1998. Revenues from our third party administration segment decreased by $29.2 million, primarily related to the transition of a block of indemnity/preferred provider organization business from The Travelers Insurance Company and United HealthCare Corporation to Seaboard Life Insurance Company (USA) products and a decrease in revenues from the block of business assumed from TMG Life Insurance Company in 1997. This reduction in fully insured revenues was partially offset by revenues from new carrier relationships. Revenues from our PlanVista Solutions segment increased by $2.8 million for the period of June through December 1999, as compared to the same seven-month period in 1998.
Agent commission expense for the year ended December 31, 1999 decreased $12.6 million, or 18.4%, to $55.9 million from $68.5 million in 1998. This decrease was realized in our third party administration segment and is consistent with the decrease in fully insured revenues for the period indicated, as described above.
In 1999, we incurred $1.2 million of restructuring costs in our third party administration segment reflecting employee terminations associated with reductions in our fully insured workforce in Tampa, Florida. We terminated 65 employees in management, claims administration, and information systems. In 1998, we incurred $1.6 million of restructuring costs in our third party administration segment reflecting employee terminations and the abandonment of property and equipment associated with closing our Framingham, Massachusetts office. We terminated 47 employees in management, claims administration, and information systems.
The Amendment requires certain prepayments upon the receipt of tax refunds, debt refinancing proceeds or the proceeds of new equity issuances and revises various other provisions relating to covenants and defined defaults. Additionally, the Amendment requires us to retain the services of an investment banker by April 30 to assist us with refinancing, and the Amendment also requires that in the event the third party administration business has not been sold or otherwise disposed of before May 30, we must prepare and submit by June 6, 2001 for approval of the Lenders a detailed plan for the alternate disposition of such business.
On June 1, 2000, we paid $2.2 million, including principal and interest, to the former owner of PlanVista Solutions as part of the additional contingent consideration relating to our acquisition of PlanVista Solutions in 1998. A principal balance of $2.0 million remains to be paid on June 1, 2001.
We do not believe that inflation had a material effect on our results of operations for the year ended December 31, 2000 or 1999. There can be no assurance, however, that our business will not be affected by inflation in the future.