NYSE Euronext's bid for European clearinghouse LCH.Clearnet would give Markit a majority stake and control of the lucrative over-the-counter swaps business, a source familiar with the plan said on Wednesday.

NYSE Euronext would have the option to increase its stake in LCH.Clearnet to 40 percent from 9 percent now, and it would get control of the Paris-based Clearnet SA through which it would clear European share trading, said the source, who was not able to speak on the record.

Markit, a privately held data provider owned by banks and others, partnered with the New York Stock Exchange parent to bid for London-based LCH.Clearnet in the last few weeks.

LCH.Clearnet confirmed it has received offers from exchanges about a tie-up, but that talks are at an early stage. A spokeswoman had no further comment.

Last week, a separate source said Nasdaq OMX Group made an offer for LCH.Clearnet. London Stock Exchange Group Plc said it is not among those in talks.

Earlier on Wednesday, NYSE Euronext Chief Executive Duncan Niederauer confirmed last week's press reports of the bid, telling analysts at a Deutsche Boerse investor day that Markit is leading the effort.

NYSE Euronext, meanwhile, is planning a $10 billion merger with Germany's Deutsche Boerse AG .

Markit declined to comment on Wednesday. A NYSE Euronext spokesman had no immediate comment.

(Reporting by Jonathan Spicer. Editing by Robert MacMillan)