Many firms benefited from increased volume and value of M&A business, but just one deal provided the key to the top five positions - the Glaxo takeover of Wellcome which, at £9.15 billion, remains the biggest-ever UK public company deal.
Slaughters' role advising Wellcome contributed much to its success in staying at the top of the table, says editor of Acquisitions Monthly Philip Healey.
Clifford Chance acted for Glaxo. Freshfields and Herbert Smith acted for the financial advisers to the companies and Lovell White Durrant advised Wellcome Trust, which held a major stake in Wellcome.
Slaughters also defended Northern Electric against Trafalgar House's hostile £1.115 billion takeover attempt.
Healey says there is a clear trend in 1995 for a "substantial increase" in the sums and volume of M&A work.
He adds: "For instance, Freshfields' 11 deals equalled its total for the whole of 1994.
"Allen & Overy in eighth place passed its 1994 total of three mandates with five deals in the first half of 1995."
Slaughters is also advising UK merchant bank Kleinwort Benson on its £977 million takeover by Dresdner Bank, which is a Freshfields client.
This should ensure that the firm retains its lead until the end of the year.