Ms McConnon, 45, collapsed and died suddenly and unexpectedly at home on Saturday.

Ms McConnon had a 25-year career in the investment sector and had just started a new role at Rathbones as chief client officer.

She leaves behind her husband, Aminul, and two young daughters Mya-Rose and Leila.

Irish-born Ms Connon was from Monaghan in the Irish Republic but had a long career with UK investment providers in London, including BNY Mellon, where she was global chief client experience office and M&G, where she was head of pan-European marketing. She had also worked for Friends Ivory & Sime and Barclays.

Her husband Aminul said in a post on LinkedIn: “I am so sorry to share some extremely sad news. On Saturday 20 May, Anne-Marie McConnon passed away suddenly and unexpectedly after collapsing at home. This has come as a huge shock and the devastation of her loss has had a massive impact on those who knew and loved her.

“Anne-Marie was a beloved wife to me and leaves two young daughters Mya-Rose and Leila, whom she adored with all her heart, her brothers and their families in Ireland and her in-laws, with whom she was incredibly close.

He described as “extremely happy, down to earth, loyal, generous, kind, and committed friend and colleague to many.”

In recent years Ms McConnon had become a campaigner for diversity and inclusion and had won awards for her work in this area. She also played a key role supporting various charitable causes, notably with the education charity CASCAID where she was a co-founder with Helen Wagstaff. She even took part in a team rowing challenge across the Irish Sea to raise money. CASCAID has so far raised £5 million across the investment industry.

A spokesperson for Rathbones said: ““Anne-Marie joined Rathbones very recently but had already begun to build some strong relationships across the business.

“She was vibrant, driven, positive and knowledgeable and all of the Rathbones team were looking forward to working with her. We are deeply saddened by this news, and our thoughts are with her family and friends at this difficult time.”

LinkedIn has seen a flood of tributes to Ms McConnon.

Investment sector marketing exec and former colleague Marion Garvey wrote: “Like so many others in the asset management industry, Anne-Marie had a huge influence on my career. I had the honour of working for her in two organisations.

"I was, and am, eternally in awe of her passion for marketing, her insatiable appetite for innovation, her unrivalled leadership and team management skills, her ability to spot and develop talent others don’t see, but above all her deep sense of always trying to do the right thing. RIP my dear friend and mentor.”

Communications and PR expert Vee Montebello wrote in response to Aminul’s post: “I am so saddened to hear this news. Anne-Marie was a very inspirational woman. A true gem of a lady. Our thoughts are with you, your daughters and all the family. Sending hugs at this very difficult time.”

Jeremy Fallows, global head of client marketing at Aviva Investors, wrote: “So desperately sad - AM was so inspiring in our industry and a lovely human being, sincere condolences to you and family.”