The deal would be worth nearly $700 million, covering the 38 percent of the Woodland Hills-based insurance company that AIG doesn't already own. The $19.75 offer would be a 19 percent premium over Wednesday's close. AIG, which is the world's largest insurer, says it has no interest in disposing of 21st Century. You might recall that 21st Century was originally called 20th Century and got its start in 1958 as a one-man operation. The idea of going directly to the insurer and not dealing with any middleman was pretty revolutionary for its time.Of course, the company nearly got wiped out after the Northridge quake (homeowners coverage might not have been the wisest bet), but ratings have steadily improved. Today, the company insures over 1.5 million vehicles.