Dec 23 (Reuters) - Talen Energy ( TLN ) plans to contest

the Federal Energy Regulatory Commission's (FERC) rejection of

an amended interconnection agreement for an Amazon ( AMZN ) data center

at its Pennsylvania nuclear plant, the company said on Monday.

The U.S. utility earlier this year sold a data center

connected to its Susquehanna nuclear power plant to Amazon ( AMZN )

and hoped to increase its capacity from 300 megawatts

to 480 megawatts.

The deal, however, faced opposition from American Electric

Power ( AEP ) and Exelon ( EXC ).

FERC, in an order issued on Nov. 1, sided with the two

regulated utilities and blocked the interconnection agreement.

Talen, last month, filed a request for a rehearing, to which

the regulator responded on Monday, stating it would address the

request in a future order.

As FERC did not decide on the rehearing request within 30

days, the decision to reject the amended interconnection

agreement is now eligible for an appeal to a U.S. Circuit Court

of Appeals, Talen Energy ( TLN ) said in a statement.

Shares of the company, which have more than tripled this

year, were up 0.6% in afternoon trading.