The 36-year-old Finley held the option on his contract for the 2009-10 season, which will be his fifth in San Antonio. The team announced Finley's decision Tuesday.
Finley finished his 14th season with averages of 9.7 points and 3.3 rebounds in 81 games. He shot a career-best 41 percent from 3-point range.
Among active players, Finley is fourth in games with 1,057 and fifth in 3-pointers with 1,422. He has career averages of 16.2 points, 4.5 rebounds and 3.0 assists.
Finley played nine seasons in Dallas after starting his career in Phoenix.