Genes Reunited sale on hold

Various media reports are that the UK Office of Fair Trading is concerned that the takeover of genesreunited by the holding company DC Thomson would result in too large a concentration of market share of genealogy databases in the UK. What's the evidence?

Choosing commercial genealogy sites from the Alexa.com rankings for all websites worldwide, with the UK and Canadian rankings shown in parenthesis (UK;Canada) shows:

ancestry.com ranked 1,179 (1,316; 684),

and for UK data sites

ancestry.co.uk ranked 10,900 (555; 15,672),
genesreunited.co.uk ranked 17,957 (908; 11,552),
findmypast.com ranked 43,984 (1,796; 21,308),
1911census.co.uk ranked 95,077 (6,558; 59,293)
scotlandspeople.gov.uk ranked 163,621 (8,607; 42,228),
thegenealogist.co.uk ranked 172,747 (11,443; 21,672),
familyrelatives.com ranked 935,071 (-;-),
origins.net ranked 1,684,261 (292,507; -)
deceasedonline.com ranked 2,843,948 (218,673; -)

Evidently a takeover that brings under a single control the 2nd through 5th most popular genealogy database sites in Britain is a bit much for the regulators to swallow without thinking about it.