In an indication the oft-sought, never-betrothed London Stock Exchange may finally be open to a merger, the British bourse on yesterday said it is exploring its options and is in talks with other exchanges.

The comment followed news Tuesday that the Nasdaq Stock Market has purchased a stake of nearly 15% in the British bourse, a move that rekindled speculation a trans-Atlantic tie-up of some sort might not be far off.

In a statement yesterday, the LSE repeated its long-held view that its prospects as a standalone company are good and that its shares are still undervalued – but then added a new wrinkle.

“Furthermore, the board is exploring the options available to it to create additional value for shareholders and customers, including discussions with other major exchanges,” the LSE said in the release. An LSE spokesman confirmed later that the LSE currently is in talks with other major exchanges. He declined to name the exchanges or to be more specific about the talks.

The LSE will meet with its shareholders next week, and the comments could be aimed at heading off any grumbling over its habitual rejection of offers.

But the statement also raises the possibility that the LSE, after years of fending off suitors such as Australia’s Macquarie Bank and German stock market operator Deutsche Boerse AG, is contemplating giving up its independence.

The change of tune follows Nasdaq’s move to buy nearly 15% of the LSE for about $782 million, making it the largest shareholder in the British exchange. Nasdaq bought the bulk of its shares from Threadneedle Asset Management and some more from Scottish Widows Investment Partnership – big LSE investors that had supported Chief Executive Clara Furse’s strategy of turning back suitors.

Nasdaq’s investment in the LSE represented a “wake-up call” for LSE management, the manager of the securities and investments practice at financial research firm Celent, Harrell Smith, said.

“They’re certainly going to take the possibility of a takeover a lot more seriously than they were before,” he said.

While the LSE didn’t say with which exchanges it is talking, The Wall Street Journal has reported that the British market recently renewed contacts with Euronext, of Amsterdam, which has been interested in the LSE in the past. A Euronext representative in London couldn’t immediately be reached for comment.

In America, market analysts have speculated the New York Stock Exchange, Nasdaq’s biggest rival,could be drawn into a contest for the LSE. The chief executive of Big Board parent NYSE Group, John Thain, has said the NYSE’s newly public stock gives it a currency for mergers. Thain has made it clear that he would like the NYSE to take part in the consolidation of trading venues. Yesterday, a NYSE spokesman, Eric Ryan, declined to comment on the LSE.

Of course, Nasdaq, whose bid for the LSE was rebuffed last month, may have something to say about another market stepping in. Nasdaq’s newly acquired position could give it a say over the LSE’s future. It would be logical for Nasdaq to eventually raise its stake further, an analyst who follows Nasdaq for Sandler O’Neill & Partners in New York, Richard Repetto, said.

(Mr. Repetto doesn’t own Nasdaq shares, but Sandler O’Neill has investment-banking ties to Nasdaq.)