UPDATE 2-Gas Natural sells 500 mln euro 4-year bond

(Adds comment from company)

MADRID, Oct 9 (Reuters) - Spanish gas company Gas Natural

easily sold 500 million euros ($644.80 million) of a four-year bond at a final price of mid-swaps plus 335 basis points and a coupon of 4.125 percent on Tuesday.

The issue, which was more than seven times subscribed, would increase liquidity and improve the financial structure of the company, Gas Natural said in a press release after the sale was finalised.

The company, rated Baa2/BBB/BBB+, started marketing the paper with initial price guidance of 345 basis points over mid-swaps shortly before 0830 GMT, according to IFR Markets, a Thomson Reuters news and market analysis service.

Barclays, CaixaBank, Citigroup, Mitsubishi and Societe Generale handled the sale.

The Spanish utility was last in the market in mid-September with a 7-year bond, which priced at mid-swaps plus 465 basis points on about 4.5 billion euros of demand.

Sentiment towards corporate debt has improved since the European Central Bank outlined in early September an unlimited government bond-buying programme to help weak economies.

Improved financing conditions have prompted a run of Spanish corporate issues since the ECB announcement, including two from Telefonica , banks Santander and BBVA and utility Iberdrola . ($1 = 0.7754 euros)

(Reporting by Jesús Aguado and Paul Day; Editing by Mark Potter and Helen Massy-Beresford)