UPDATE 2-TGS-Nopec shares leap on upbeat Q4 guidance

(Add analyst comments, Wavefield comment, updates share price)

By Aasa Christine Stoltz and Ole Petter Skonnord

OSLO, Jan 7 (Reuters) - Norwegian seismic surveyor TGS-Nopec (TGS.OL: Quote, Profile, Research) said on Monday it expected 2007 revenue growth at the lower end of its forecasts and fourth quarter results better than projected, boosting its shares sharply on the Oslo bourse.

TGS-Nopec, a supplier of seismic surveys to the oil and gas industry, published new estimates after it had to exclude results from its planned merger partner Wavefield Inseis (WAVE.OL: Quote, Profile, Research) amid a dispute over their tie-up.

Shares in TGS-Nopec rose 9.0 percent to 80.80 crowns by 0947 GMT, valuing the company at about 8.6 billion Norwegian crowns ($1.61 billion), while shares in Wavefield were up 0.7 percent at 43.50 crowns, valuing it at 5.6 billion crowns.

The Oslo bourse's benchmark index was down 0.9 percent.

TGS last month launched a formal process, which has subsequently led to arbitration, to resolve the dispute over the $1.2 billion takeover, which was put on ice by Wavefield after an unexpected TGS profit warning for the third quarter knocked the value of the deal to Wavefield shareholders.

Some Wavefield shareholders believed TGS knew it had missed market estimates of third-quarter earnings when voting for the merger.

Wavefield Chief Excutive Atle Jacobsen told Reuters that the new TGS estimates for the fourth quarter removed some of the uncertainty around its results.