Dec 19 (Reuters) - Buyout firm TPG is in

advanced talks to buy the fiber unit of tower operator Crown

Castle ( CCI ) for about $8 billion, a person familiar with the

matter said.

Shares of the Houston, Texas-based Crown Castle ( CCI ) were up 2.1%

in trading after the bell.

A deal for the fiber and wireless units could be announced

within weeks, the source said.

However, the source added that while no final decision has

been made, the discussions could fall through or another buyer

could emerge.

The development was first reported by Bloomberg News.

TPG, along with fiber network owner Zayo Group, was vying

for Crown Castle's ( CCI ) fiber and wireless assets, Reuters had

reported in October, citing people familiar with the matter.

If the talks are successful, the deal would come at a time

when mergers are heating up in the fiber industry.

With the rapid growth of fiber broadband boosting business

for infrastructure providers such companies such as Crown Castle ( CCI )

are being seen as attractive acquisition targets.

Spokespersons for TPG and Crown Castle ( CCI ) declined to comment.

The development comes at a time when Crown Castle ( CCI ) has been

exploring options for its fiber assets, after reaching a deal

with activist investor Elliott Investment Management over

shaking up its board.

Crown Castle ( CCI ) co-founder Ted Miller had told Reuters in

February that the company could fetch as much as $15 billion by

selling its fiber assets if it let him and his partners join its

board of directors.