UPDATE 1-Appeal jeopardizes Mexico's frequency auction

* Judge accepts MVS Net appeal vs auction

* Claim over govt's renewal of parent's licenses (Releads, adds MVS comment, reason for appeal)

MEXICO CITY Feb 3 (Reuters) - A Mexican judge accepted an appeal filed by broadband provider MVS Net against a frequency auction, possibly jeopardizing one of the government's key plans to boost competition in the telecommunications market.

A federal judge in Mexico City accepted the appeal filed by MVS Net against the process, which seeks to tender blocks of frequency in the 1.9 GHz and 1.7 GHz bands, the company's parent MVS Comunicaciones said in a release.

MVS Net offers broadband services to several telephone companies in Mexico. Its argument for the appeal is that the government has yet to decide on the renovation of MVS Comunicaciones' licenses to operate in the 2.5 GHz band that expired five years ago.

MVS Comunicaciones said the uncertainty has kept it from investing heavily to deploy new infrastructure in Mexico.

It was not immediately clear if the judge's acceptance of MVS Net's appeal could bring the auction to a full stop.

The tender of added capacity, one of two government initiatives to bolster competition in a telecom market dominated by tycoon Carlos Slim, is meant to make way for the entrance of a new cellphone operator and expand existing services of current market players.

Telephone companies belonging to tycoon Ricardo Salinas had filed similar appeals against the frequency auction recently, but they were dismissed this week, Reforma newspaper said on Wednesday.

Some 40 companies, including media giant Televisa (TLVACPO.MX)(TV.N) and Spain's Telefonica (TEF.MC), have purchased terms for the auction, Reforma added.

Winners were expected to be announced in June.

Additionally, the government last week launched a tender for two strands of state-owned optical fiber that will provide private companies with a new backbone to transport television, telephone and Internet.

Slim's America Movil (AMXL.MX) (AMX.N), which could benefit from a delay in competitors accessing to more capacity, traded 2 percent higher near the session's close. It is the leading cell phone company in Mexico. (Reporting by Cyntia Barrera Diaz; Editing by Lisa Von Ahn, Bernard Orr)