UPDATE 1-Nigeria's GT Bank plans $1.3 bln debt issue

* Bond would be among first in Nigeria in 3 years

* First Bank also planning bond issue

* Central Bank seeking to encourage corporate issuance

(Adds background)

LAGOS, July 31 (Reuters) - Nigeria's Guaranty Trust Bank GTB.LG will seek approval for a 200 billion naira ($1.3 billion) debt issue at an extraordinary general meeting on Aug. 27, it said in a notice published on Friday.

The notice in the This Day newspaper said the tranche sizes and dates of the issue would be determined by the bank directors and gave no details on what the funds would be used for.

GT Bank is the second Nigerian bank this week to announce plans to raise debt in what would be the first corporate bonds in sub-Saharan Africa's second-biggest economy in three years.

First Bank FBNP.LG said on Monday it wants to raise a 500 billion naira bond and will hold an extraordinary shareholders meeting to vote on the issue on Aug. 20. [ID:nLR209329]

Nigerian companies have not ventured into the corporate bond market for several years because of the high cost of issuing debt and tax concerns. Access Bank ACCE.LG was the last institution with its 13.5 billion naira bond in October 2006.

New central bank Governor Lamido Sanusi said earlier this month he wanted more companies to raise funds through the bond market.

Sanusi said the regulator would seek to reduce the cost of corporate bond issues and work with tax authorities to have a tax-free yield curve. [ID:nLD726472] (Reporting by Chijioke Ohuocha; Writing by Nick Tattersall; Editing by Hans Peters)