The phrase "but markedly" is correct and can be used in written English.
For example, "Sales in the first quarter were down, but markedly increased in the second quarter."
Another diagnostician said she was "not lunatic but markedly neurotic".
Sox2 deletion in the epidermis does not impair skin homeostasis but markedly decreases skin tumour initiation.
Results: Catheters had similar area moments of inertia, but markedly different elastic moduli.
One saw the same excitement but markedly less merriment, and the crowd looked more mature, even sober.
This is a movie that is above par for a sequel but markedly inferior to the original.
Kite flying itself is equally effective, with similar ups and downs but markedly less long-term paranoia.
In vitro, pAd-GITRL-BMDCs greatly enhanced effector T cells proliferation but markedly abrogate the suppression of Treg cells.
It has been shown to cause cochlear disruptions in rats but markedly less ototoxic effects in guinea pigs.
The energy distribution is similar in both but markedly different from the other recorded drumming, indicating it is a third bird.
Mr Christensen points out that innovators often start by offering products that are cheaper, but markedly inferior.
That is still high by international standards, but markedly better than the rate of 60 in 2003.
