(Sharecast News) - Stride Gaming lost a third of its market value after the online gaming company said the UK's gambling regulator planned to slap a big fine on one of its businesses.The AIM-listed company said the UK Gambling Commission had told one of its subsidiaries it intended to issue a "significant financial penalty" after reviewing how it conduct activities. The penalty notice is not final, Stride said."The company is taking advice as to its options from its advisers, which include making representations to the UKGC about the proposed financial penalty and, if need be, appealing the ultimate decision of the UKGC and/or the size of any penalty," the company said.Stride's shares fell 33% in early trading and were down 31.75% to 86p at 10:05 BST.The company trades through multiple brands selling online bingo, casino and slot gaming. Stride says it is the UK's third-biggest online bingo operator with a 12% market share.