* Vivendi offered 10.5 bln euros cash plus 46 pct of new co
* Rival Numericable bid offers 11 bln in cash and 32 pct
* Bouygues would spin off new entity after acquisition
* Vivendi expected to review bids in coming weeks (Adds sources on Numericable not raising bid)
By Leila Abboud and Matthieu Protard
PARIS, March 6 (Reuters) - French conglomerate Bouygues has made an offer for the telecoms arm of Vivendi that would give the seller a bigger potential payday than a rival bid but take longer to arrive and face more regulatory risk.
Bouygues, with interests from telecoms to construction, offered 10.5 billion euros ($14.4 billion) in cash for Vivendi's SFR and 46 percent of the new company in a planned spin-off.
A competing bid from French cable operator Numericable included 11 billion euros in cash, granting Vivendi a 32 percent stake in the new company, sources said earlier.
A tie-up between SFR and Bouygues would create Europe's seventh-biggest telecoms group by sales. In France it would rank ahead of current market leader Orange in terms of market share.
If accepted by Vivendi and approved by regulators, the Bouygues offer announced on Thursday would consolidate the French market to three from four mobile players, potentially easing a price war sparked by low-cost operator Iliad's entry into the mobile arena in January 2012.
The price war is partly why Vivendi has been seeking to cut its exposure to the capital-intensive telecoms business to focus more on pay-television and music. It was preparing to split SFR into a separately listed company this summer, but is now open to offers for the business.
The battle for SFR could hinge on how Vivendi's board gauges the value of the shares it will receive in the new group, its appetite to wait out an antitrust review that could take a year and which company it sees as a better long-term partner, people close to the deal said.
Vivendi plans to review the offers in the coming weeks.
The government has also signalled that it could weigh in to protect jobs - a key concern with the French unemployment rate hovering at 10 percent - and ensure that the operators keep promises to invest in key infrastructure.
Both bidders have offered some assurances on employment. Numericable has said it would be hiring, whereas Bouygues said its offer would involve no forced redundancies, implying voluntary departures are possible.
Bouygues, a family-controlled group led by billionaire Martin Bouygues, potentially has the tougher battle to win SFR because merging France's No.2 and No.3 mobile operators would attract intense regulatory scrutiny.
Numericable, backed by billionaire entrepreneur Patrick Drahi, would not face such obstacles because it is not a force in mobile. It owns a cable network serving two thirds of French households and sells broadband and television services.
Bouygues Chief Financial Officer Philippe Marien said talks had not yet begun with French antitrust regulators but the group is ready to take steps to protect competition. "We will do what it takes for the market to stay competitive," he said.
Sources said earlier that Bouygues would be ready to sell mobile spectrum and some of its 15,000 antennas. Iliad, which has been racing to build its mobile network, would be the obvious buyer and beneficiary of such disposals, analysts said.
Marien said Bouygues would also help so-called virtual mobile operators, which rent capacity on other carriers' networks, to preserve competition. Similar measures helped to get telecoms deals approved in Austria.
The Bouygues deal would split out the combined company into a new entity in which Bouygues would remain the largest shareholder with 49 percent. Vivendi would have 46 percent and outdoor advertising group JCDecaux, long an investor in Bouygues Telecom, would own the remaining 5 percent.
The new company would then make a share issue to which Bouygues would not subscribe. Marien said 3 billion euros would come from the issue and asset disposals to placate regulators.
Once listed, Vivendi would be clear to sell off 15 percent of the new company, Bouygues said, and would subsequently be free to sell its remaining interest when it sees fit.
Bouygues said its bid valued SFR at 14.5 billion euros before cost savings from the deal and 19 billion euros after.
For its part, Numericable sees its bid as valuing SFR at 14.5 billion euros before cost savings, said a source close to the company. Numericable will not raise its offer because it is confident that it is more attractive than Bouygues, two people close to the situation said on Thursday night.
How much costs can be cut from the tie-ups is disputed.
Bouygues estimated the net present value of the cost savings from the deal would be 10 billion euros, with 80 percent coming from operational costs and 20 percent from network investments.
Numericable has not given a comparable figure. The person close to the group said synergies could be 12 billion euros.
Barclays analysts said the Bouygues deal was likely to generate double the synergies of Numericable's offer.
Shares in Bouygues closed up 6.6 percent. Numericable fell 5.3 percent, Iliad rose 7 percent and Vivendi rose 1 percent.
Bouygues was advised by HSBC and Rothschild on its bid. HSBC is financing the debt for the offer. ($1 = 0.7278 euros) (Additional reporting by Gwenaelle Barzic; Editing by Andrew Callus and David Goodman)