By Linda Chiem (August 6, 2015, 6:09 PM EDT) -- Private equity giant The Blackstone Group LP has teamed up with buyout fund Hellman & Friedman to put in a bid for Worldpay Ltd., the British credit and debit card payment processing company, Reuters reported Thursday. No word on how much they're looking to offer but the rumored bid comes as Worldpay's current private equity owners, Advent International and Bain Capital LLC, prepare to take Worldpay public with a London listing, according to the report. Advent and Bain Capital in 2013 picked up the remaining stake in Worldpay from Royal Bank of Scotland Group PLC. The private equity firms had previously bought the controlling stake in Worldpay from RBS in a $3.2 billion deal in 2010....