A 15-year-old merger between the London Stock Exchange and Deutsche Boerse is back on

Germany's Deutsche Boerse and the London Stock Exchange are in merger talks.

The deal, first proposed in May 2001 but since abandoned, is at an advanced stage and the two groups are "in detailed discussions about a potential merger of equals of the two businesses," according to an LSE statement on Tuesday.

"The Boards believe that the Potential Merger would represent a compelling opportunity for both companies to strengthen each other in an industry-defining combination, creating a leading European-based global markets infrastructure group."

"The combination of LSE and Deutsche Boerse's complementary growth strategies, products, services and geographic footprint would be expected to deliver an enhanced ability to provide a full service offering to customers on a global basis," the company said on Tuesday.

The potential deal also marks another success for M&A specialists over the big banks, with nine-person boutique Robey Warshaw scooping the lead role advising the LSE and Perella Weinburg Partners advising Deutsche Boerse.

A merger between the companies almost happened in 2001, but was scuppered by a bid from Sweden's OM for LSE. Deutsche Boerse tried again in 2004 but abandoned the bid in 2005.

Robey has had a stellar 12 months and is advising on a series of multi-billion pound mergers, including the tie-up between SAB Miller and Anheuser Busch Inbev.

LSE shares went ballistic on the news, up more than 18%: