* America Movil to back 1 billion euro capital increase
* To pay 7.15 euros/share for rest of Telekom Austria
(Adds comments from analysts, details of deal, paragraphs 4-6, 9-10, 14-15)
VIENNA/MEXICO CITY, April 23 (Reuters) - Mexico's Carlos Slim struck an 11th-hour deal on Wednesday with the Austrian government that could give him control of Telekom Austria and allow the multi-billionaire to consolidate his foothold in Europe as he expands outside the Americas.
Slim's telecoms group, America Movil, agreed to back a 1 billion euro capital increase for Telekom Austria and to pay 7.15 euros a share for the company's outstanding stock, in a co-ownership deal combining its stake with that of Austrian state holding company OIAG.
The agreement is a coup for America Movil, which is facing increasing regulation and competition in Latin America, especially in its home market of Mexico. It has also suffered various setbacks in its attempts to expand in Europe.
Rudolf Kemler, the head of OIAG, said in a statement the accord guaranteed a blocking minority for the state holding company and would enable Telekom Austria to embark on "massive growth" in Eastern and Central Europe.
The agreement will stand for 10 years with an option to extend for a further five, the OIAG said, adding that it would hold the right to designate the chief executive of Telekom Austria and its supervisory board chairman.
The price America Movil will pay per share is a premium of 10.7 percent over the six-month average stock price for Telekom Austria, or the minimum bid required.
Latin America's biggest telecoms company already holds 26.4 percent of Telekom Austria. OIAG has 28.4 percent.
The deal should allow Slim to begin consolidating his European ventures, which began in 2012 with investments of more than $1 billion in Telekom Austria and $3.4 billion in Dutch group KPN.
Slim is under attack from telecoms regulators in Mexico, where America Movil has around 70 percent of the mobile market and 80 percent of fixed line business. The regulator last month unveiled a battery of measures to curb the company's power.
That made Wednesday's agreement a timely boost for Slim, said Stefan Astheimer, an analyst at Howe & Rusling. But it remained to be seen how the deal would pan out, he added.
Wednesday's agreement envisages pooling the stake held by the OIAG with the stake held by America Movil in a syndicate in which both parties would have to vote in unison on major issues.
The syndicate deal allows Slim, one of the world's richest people, to raise his holding in Telekom Austria. The OIAG said its stake would remain a minimum of 25 percent plus one share.
The OIAG has declined to commit to keeping pace with Slim.
Still, Jose Martinez, Slim's biographer, said it was obvious Austria did not want to cede too much power to the tycoon.
"They're putting a few curbs on him in to avoid ... what happened in Mexico happening," Martinez said.
Slim's original purchase of Telekom Austria and KPN stakes took advantage of market valuations seen as cheap at the time.
Telekom Austria was then battling fierce competition from three other operators in the country, but a consolidation of the market to three carriers was already in view, and it has subsequently eased the price rivalry somewhat.
Slim made an unsolicited offer for the rest of KPN last year and was rebuffed. He was keen to avoid a similar fate in Austria, where he courted politicians with promises to safeguard the Austrian headquarters and give the government veto rights.
Doubts about the agreement briefly surfaced earlier on Wednesday, when labor representatives unhappy with the proposal boycotted a meeting designed to rubber-stamp the deal.
Telekom Austria shares closed down 3.19 percent at 6.65 euros before the agreement was sealed. America Movil shares closed up 0.47 percent at 12.90 pesos. ($1 = 0.7248 Euros)
(Additional reporting by Elinor Comlay in Mexico City and Derek Brooks; Editing by David Goodman, Leslie Adler, Andre Grenon and Mohammad Zargham)