EPS of $0.83 decrease by $0.05 both including and excluding the effects of foreign exchange. Lower revenues and higher technology and facilities and costs were partially mitigated by improved gross margin and lower interest expense. For the six months, revenue of $877 million was flat on a currency neutral basis but grew 3% including the positive foreign exchange impact. Adjusted EPS for the six months fell 2% to $1.51, excluding favorable foreign exchange adjusted EPS fell 6%, reflecting the top line results and higher technology and facility costs.
Year-to-date gross profit as a percentage of revenue was 70.1%, 1.3% ahead of the prior year figure of 68.8% due to increased digital product sales, product mix and timing. Year-to-date shared services and administrative costs of $194 million were up 10% due to ongoing investments in digital products and infrastructure and increased facility costs related to the consolidation of operations and the doubling up of occupancy costs during the payout period as we move to new premises in Singapore, San Francisco and the UK.
Free cash flow for the first six months was a use of $88 million. $63 million greater than the prior year. Lower cash earnings as a result of the timing of subscription cash collections, higher non-cash subscription revenue and higher capital spending on technology were the major driver of the higher cash usage. Subscription cash collection delays relate to the timing of 2012 subscription renewal negotiations and are expected to recover in the third and fourth quarters.
Net debt was $428 million at the end of the quarter, down from $545 million a year earlier. During the quarter, Wiley repurchased 600,000 shares at a cost of $28 million. Now I would like to provide some information regarding performance of Wiley’s global businesses. STMS second quarter revenue of $251 million increased by 3% or 1% excluding the favorable effect of foreign exchange. Currency neutral journals revenue grew by 1.5% over prior year, reflecting solid underlying calendar year 2011 subscription and reprint sales growth. Partially offset by lower backfile sales and the adverse impact from the timing of issue publication.