UPDATE (10:30am on Thursday) -- If the reported promotions take place, Beane will be elevated to a larger role similar to that of Tony La Russa in Arizona, CSNBayArea.com has learned.
The Diamondbacks named La Russa their chief baseball officer in May of 2014.
With several teams looking to fill general manager openings this offseason, A's assistant GM David Forst could be a popular target.
But it's unlikely that he will have a chance to interview with another team.
According to Fox Sports' Ken Rosenthal, the Mariners are interested in Forst for their vacant GM position, but the A's are expected to promote Forst to general manager and elavate current GM Billy Beane to team president role.
A timetable for the moves is unclear, according to Rosenthal.
Beane, who took over as A's general manager in 1997, is currently the longest-tenured GM in baseball. He assumed that distinction when the Giants promoted Brian Sabean from GM to executive vice president of baseball operations in April and named Bobby Evans as their new general manager.
On Sept. 9, the A's announced a two-year extension for manager Bob Melvin. At the time, A's managing partner Lew Wolff would not comment on a report that Beane and Forst are in line for promotions of some sort within the front office, saying those decisions typically get considered in the offseason.
Last December, the Dodgers plucked then-assistant GM Farhan Zaidi from the A's front office to be their general manager.