By Sara Sjolin
LONDON (MarketWatch) -- European stock markets showed mixed moves at the open on Monday, as mining firms dropped after a disappointing Chinese growth reading, while heavyweight drug firms were on the rise. The Stoxx Europe 600 index XX:SXXP +0.05% gained 0.1% to 292.53, but was swinging between small gains and losses. Data from China were in focus and sending mining firms lower, after a report showed gross domestic product for the first quarter rose 7.7%, falling short of expectations of an 8% rise. Shares of heavyweight miner Rio Tinto PLC UK:RIO -2.95% RIO -1.27% AU:RIO -3.18% lost 2.9%, while Randgold Resources Ltd. UK:RRS -4.92% slumped 5%, tracking gold prices lower. On a more upbeat note, drugmakers posted broad-based gains, with shares of Roche Holding AG CH:ROG +1.33% up 1.5%. Among country-specific indexes, the U.K.'s FTSE 100 index UK:UKX -0.06% slipped 0.1% to 6,376.33, while Germany's DAX 30 index DX:DAX +0.25% gained 0.2% to 7,760.55. France's CAC 30 index FR:PX1 +0.30% rose 0.3% to 3,739.32.