正则表达式 – 如何使用sed搜索和替换,而不包括一组字符？

它会破坏list.txt中的以下数据,使每个公司名称都在一行上,公司名称在逗号后面,但有时“Inc”,“Ltd”,“LLC”和“The”跟随公司.

这是非常先进的正则表达式,我似乎无法得到.

sed -re 's/([a-zA-Z.]),(Need code here)/1n2/g' list.txt

list.txt包含以下数据：

Electronic Arts,Inc.,Electronic Arts Ltd.
Activision Publishing,ak tronic Software & Services GmbH
Coplin Software
Electronic Arts,Inc.
Electronic Arts,Inc.
In-Fusio
Activision Publishing,Inc.
Domark Ltd.
Electronic Arts,Inc.
Aspyr Media,Electronic Arts,Inc.
Activision Deutschland GmbH,Activision Publishing,ak tronic Software & Services GmbH,Noviy Disk,Square Enix Co.,Ltd.
Electronic Arts,Electronic Arts Ltd.
Electronic Arts,Electronic Arts Square,K.K.,MGM Interactive
Electronic Arts Ltd.

预期输出(注意逗号)：

GarageGames,Inc.
The Avalon Hill Game Company
Microforum International,The
Telenet Japan Co.,Ltd.
Glu Mobile,Inc.
Warner Bros. Digital Distribution
Atari,Inc.