Sept 12 (Reuters) - Morgan Stanley has hired two key executives from Bank of America Corp's Merrill Lynch unit as it builds out its digital offering within wealth management, the investment bank confirmed.

The hires come as Morgan Stanley is focusing on clients with bigger bank accounts and increasingly referring those with fewer assets to call centers and online investing platforms. It is also looking for new ways for technology-savvy clients to interact with their advisors, including mobile apps and texts.

Jaime Sobrepera started this week at the New York-based bank as the head of its call center for clients, called the client advisory center. Sobrepera had worked at Merrill Lynch for nearly 30 years where he held a variety of roles including running the advisor centers at Merrill Edge, the firm's online, call-center and branch-based brokerage platform.

Paul Vienick, who ran Merrilledge.com and its self-directed platform, will join Morgan Stanley in November. Vienick will help build out the bank's client portal Morgan Stanley Online and its mobile platform.

A Morgan Stanley spokesman confirmed the hires.

Morgan Stanley, unlike some of its Wall Street peers who have announced partnerships with algorithmic-based investment platforms known as "robo-advisors," has repeatedly said it believes the best way to use automated technology is alongside human advisors rather than as a standalone product.

"You said robo, we said digital - it's not the same," Morgan Stanley CFO Jonathan Pruzan said on Monday, responding to a question during an industry conference.

Morgan Stanley executives say their digital push is not to attract new mass affluent clients, as Merrill Edge has done. The bank is focused on doing more business with existing clients, particularly those with greater than $1 million in investable assets. (Reporting by Olivia Oran in New York)