MegaFon had aimed to raise around $2 billion from its initial public offering this year, but several sources have said it would have to delay the share sale until 2013 if it did not get the nod from the UK Listing Authority (UKLA) in time.

MegaFon has cleared and resolved any material issues with the UKLA, a source familiar with the situation said on Saturday. Official approval is expected when MegaFon's IPO prospectus has been completed, the source said.

?The company is expected to make a formal statement on the IPO launch in the coming weeks. The deal could happen in late November or early December, before capital markets wind down for the end of the year, sources have said.

The float by MegaFon, which is controlled by Russia's richest man Alisher Usmanov, would rank as the biggest by a Russian company since Internet search firm Yandex (>> Yandex NV) raised $1.4 billion when it floated in New York in May 2011.

LISTING CRITERIA

The UKLA approves an IPO prospectus when it is satisfied a company has met its listing criteria. Among issues the UKLA typically examines is the shareholder structure. Any particular concerns are typically listed in the 'risks' section of the prospectus.

Usmanov told Reuters in September that he would fold his stake in MegaFon and other assets into a new holding company, co-owned by one of his partners Vladimir Skoch, father of billionaire Russian lawmaker Andrei Skoch, who helped build up iron ore miner Metalloinvest.?

?Goldman Sachs (>> Goldman Sachs Group, Inc.) dropped out as an underwriter of the IPO in October, which one source familiar with the situation said at the time was over unspecified shareholding concerns that were not related to Usmanov.?

?The UKLA was now satisfied with the information provided with regard to the new holding company structure, one of the sources said.

?The UKLA gave the go-ahead for the offering on Friday, said a second source familiar with the situation, meaning the float can happen this year. A third market source also said the IPO had received the green light but gave no more details.?

?A fourth source familiar with the matter said work still remained to be done on the prospectus, indicating a final sign off may not yet have been received.

?"We intend to complete the IPO this year and that will be on the basis of an approved prospectus from the UKLA," said a spokesman for MegaFon. He declined to comment further.?

?A spokesman for the UKLA declined comment.?

MegaFon announced plans for the offering in early October but later said it would put off launching the roadshow until it had published its third-quarter results.

Those results, released on Thursday showed gains in revenues, earnings and margins that analysts said would boost MegaFon's goal of achieving a valuation comparable with its competitors, MTS and VimpelCom (>> VimpelCom Ltd (ADR)).

Sources have said a stake of around 15 percent in MegaFon could be offered to investors in London and Moscow, with Nordic telecoms firm Teliasonera (>> TeliaSonera AB) selling down its stake.

MegaFon also plans to pay down some of the debts it took in on in a restructuring deal in April that saw tycoon Mikhail Fridman exit the business and Usmanov secure overall control.

(Reporting by Megan Davies; Editing by Douglas Busvine and Sophie Hares)

By Megan Davies