UPDATE 2- WL Ross to invest $80 mln in Spicejet

(Adds byline, analyst quote, background, updates share price)

By Rakesh Sharma

NEW DELHI, July 15 (Reuters) - Budget carrier SpiceJet Ltd (SPJT.BO: Quote, Profile, Research) said on Tuesday U.S. investor WL Ross & Co LLC will invest about 3.45 billion rupees ($80 million) in the company, helping the shares surge 16 percent in a weak Mumbai market.

The funds comprise more than half of SpiceJet's equity base of 6.73 billion rupees, based on the stock's close on Monday and total shares as on March 31, but Director Ajay Singh said WL Ross would hold less than 15 percent of the carrier.

"This is a significant investment for SpiceJet to retain its low-cost model. This will strengthen SpiceJet and help it in its expansion plans," he told Reuters over the telephone.

Singh said the investment details will be made public only after the final documentation is completed by the next fortnight.

CNBC TV18 channel reported that Ross will acquire foreign currency convertible bonds held by Goldman Sachs (GS.N: Quote, Profile, Research) and the Dubai government's investment agency Istithmar.

The bonds will turn convertible in 2010 which is when Ross will become stakeholder, the channel said, without identifying its sources. SpiceJet officials did not return phone calls to confirm the report.

The fresh capital infusion will help the carrier to gain an edge in terms of operational efficiency, analysts said.