Staff

As Chief Executive Officer at ACG, Brent oversees all aspects of the organization's operations and plans for strategic growth.

He has a long career in middle market M&A, with more than 25 years of sell-side and buy-side advisory experience, closing more than 200 transactions with a combined value of more than $1 billion. He also has a long and dedicated history supporting ACG in a volunteer capacity, serving in multiple positions on the ACG Board of Directors, and was recently honored with a Lifetime Achievement Award at the 2023 DealMAX event.

Brent has been an active participant in numerous chapter leadership events for 20+ years, forming deep connections with ACG's chapter network. He has attended more than 250 ACG events throughout the U.S. and has been a key member of his local ACG St. Louis chapter, serving in multiple positions including Board President, Membership Chair, Chair of the Corporate Peer Group, as well as Chair of a key multi-chapter Midwest event, the Growth Conference.

Immediately before joining ACG, Brent served as Managing Director at Nolan & Associates, a leading boutique investment banking firm with a focus on the middle market.

Prior to joining Nolan, Brent spent 18 years as Managing Director of a St. Louis independent investment bank. He also has extensive experience growing private companies through acquisitions, serving as CEO of a food manufacturing company that more than quadrupled its sales in eight years, and continuing to serve on the boards of several privately held companies.

Brent and his wife, Celeste, have two sons, and when he is not attending ACG events or board meetings, he enjoys traveling, reading and cooking, which he developed a passion for while working in an Italian restaurant in college.

Every organization needs a compass. Shannon is that to ACG. Since 2010 she’s been a steadfast steward to board volunteers, chapter executives and staff. Shannon began her career in politics and government with the Illinois State Senate, then leveraged her governance understanding to serve the business community through the Illinois Commerce Commission. Shannon later joined Smith Bucklin as an association manager juggling myriad responsibilities, including ACG. When ACG transitioned to a staff-driven organization, Shannon was one of the first employees to join. Her governance experience is invaluable to ACG’s Global Board of Directors; her collaborative style and organization skills are unmatched - evidenced by successful implementation of ACG’s web and CRM platforms. Shannon ensures the senior management team is aligned with the board’s strategic objectives, and supports staff exceeding the expectations of internal and external stakeholders.

Michael Rivera oversees ACG's chapters, operations, membership, marketing, communications and leadership development across local, regional, national and international levels.  With nearly twenty years of experience in new business development, management consulting and strategic planning, he creates and executes scalable solutions that support ACG's mission and vision. Before becoming Chief Strategy Officer, he was Executive Director for ACG Los Angeles and CEO for the ACG West Region. 

He is the Founding Director of the University of Southern California’s Marshall Venture Fund, an industry-agnostic venture capital fund investing in early-stage startups founded by USC students, alumni, faculty and staff. Michael developed and taught a second-year MBA course at USC called the Marshall Venture Lab and served as a mentor for Quake Accelerator and Blackstone LaunchPad in Los Angeles. 

Before joining ACG, he spent over a decade as the Founder and President of Santa Monica-based 6th Street Ventures, an early-stage investment firm. He co-founded Westside Trading Company, a commodity trading firm based in central California, where he managed international banking and operations while actively trading commodities.  

Michael began his career as an attorney and registered lobbyist in Washington, D.C. representing corporate clients. He received his J.D. from the Pennsylvania State University School of Law and his B.A. from Georgetown University.   

Christine Melendes returns to ACG as the Chief Commercial Officer. In this role she’ll be responsible for formulating the strategy and architecture for ACG’s long-term success and sustained growth which will include assessing, aligning, and overseeing product development, analyzing market trends and customer/member needs to identify new ways to engage and serve ACG members as well as strengthen and grow the hugely successful DealMAX event held each spring.

Christine is returning to ACG, having previously spent 10 years with the organization, and brings decades of experience in non-profit management where she built her career by developing meaningful board/volunteer/membership relationships, cultivating significant partnerships, expanding market footprints, and navigating complex engagement roadmaps. She has a deep understanding of breaking into new markets, multi-program event planning and oversight, and is a strong leader in cross-functional work in membership, partnerships, operations, communications and marketing.

Prior to rejoining ACG, Christine was at the American Epilepsy Society (AES), where she was the Associate Executive Director, Operations & Business Development. In her role she was focused on sustained and long-term revenue development of more than $8m from membership, exhibit sales and sponsorship, event registration, product marketing, and development. Additionally she lead the operations and IT teams.

Christine earned an MBA from Loyola University Chicago and an BA from the University of Wisconsin-Milwaukee. She is a Certified Association Executive (CAE) and is the 2015 recipient of the “Association Professional Achievement Award” presented by the Association Forum of Chicagoland. She has spoken on the topics of sponsorship revenue, membership development and revenue, and career advancement at association industry events throughout her career. She is proud to have led the team at ACG on a project that earned the organization a 2016 “Power of A Award” from ASAE.