The London Stock Exchange has warned that its proposed £21bn merger with Germany’s Deutsche Borse is likely to be blocked by the European Commission.

The LSE said the commission had made the “disproportionate” request that it sells its stake in MTS, an electronic market, in order to satisfy concerns over competition.

It added that, with its shareholders’ best interests in mind, it could not go ahead with the request but would continue to pursue the merger.

The LSE said: “Based on the commission’s current position, LSE believes that the commission is unlikely to provide clearance for the merger.

“Nevertheless, the LSE board remains convinced of the strategic benefits of the merger and recognises the strong support from shareholders for the transaction.

“LSE will continue to take steps to seek to implement the merger.”

LSE and Deutsche Borse announced their plans for a “merger of equals” last year, saying the combined European operation would be batter placed to complete against rival in the United States.

News of the commission’s demand in respect of MTS emerged earlier this month. LSE had already agreed to sell LCH, part of its clearning business, in order to satisfy regulatory concerns.