Complex sentence: Google withdrew from sponsorship of the event claiming the new rules did not require full disclosure from winners, but offered a separate "Pwnium" contest with a $1,000,000 prize purse for Chrome specific exploits.
Split into simpler sentences: Google withdrew from sponsorship of the event claiming the new rules did not require full disclosure from winners. Google offered a separate "Pwnium" contest with a $1,000,000 prize purse for Chrome specific exploits.