• by March 29, 2011

Boston has been a beacon of agency activity for top-level digital hiring this week, with executives from Modernista! and One-to-One Interactive moving to two Havas entities: creative shop Arnold Worldwide and media agency MPG. Also, Publicis Groupe's Digitas made a key promotion as it launched a new business unit.

Continuing its rapid expansion in the digital realm, Arnold hired former Modernista! president Matt Howell, who helped bring in seven other exiles from that beleaguered agency. Howell, who also ran Modernista!'s digital group, joins Arnold in the new position of managing partner, global chief digital officer.

MPG tapped Armin Molavi, who had been senior vice president, media and brand planning, at One-to-One, as its senior vice president, strategic planning, another new position. Molavia, a digital agency veteran who will work out of MPG's Boston office, has also been vice president, group marketing director at Digitas. Prior to that, he held marketing positions at Arnold.

Molavi will report to Sasha Savic, another Publicis veteran, who was recently named Havas Media's first chief commercial officer, North America.

Digitas formally announced a new unit called Digitas Business, which will handle all business-to-business marketing and communications. To run the unit, Digitas promoted Dennis Reilly from senior vice president of marketing to senior vice president/director of Digitas Business.

Arnold, meanwhile, also created two other new top digital positions:

•SVP/director of social media, filled by Sebastian Gard, who held a similar position at Modernista!

•Vice president/director of user experience, given to Bob Goodman, who had been user experience director at Modernista!

Also joining Arnold from Modernista! are Greg Murphy and Matt Karolian as social media managers, and Lauren Shea, Brendon Volpe, and Todd Buffum as digital producers.

In the past few years, Modernista! has suffered losses in both clients and personnel, including co-founder Lance Jensen's move to Interpublic's Hill, Holliday as chief creative officer earlier late last year.

Arnold said it has now hired more than 60 digital staffers -- upping the total number to 150 -- since Andrew Benett took the agency's reins as global CEO a year ago in a move from sister shop Euro RSCG. (He's also global chief strategy officer of Havas Worldwide.)

Those other hires have included Graham Cousens as senior vice president, director of digital production, from MDC Partners' Crispin Porter + Bogusky, and three vice president/creative directors: Steve Caputo from Interpublic's R/GA, Jose Luis Martinez from Goodby Silverstein and Tom Morhous from AKQA.

Arnold's top clients in the digital realm include Carnival Cruise Lines, Progressive and the anti-smoking group Truth.