— Appeal by defendant from a judgment of the County Court, Nassau County (Baker, J.), rendered September 8, 1986, convicting defendant of murder in the second degree, upon his plea of guilty, and imposing sentence.
Ordered that the judgment is affirmed.
The defendant waived his right to seek appellate review of the denial of his motion for a severance as a result of his guilty plea (People v Decker, 135 AD2d 920).
The court did not improvidently exercise its discretion in denying the defendant’s presentence motion to withdraw his plea of guilty, since the allegations made in support of that motion were conclusory and unsubstantiated (see, People v Pettiford, 133 AD2d 856).
Finally, the sentence imposed was appropriate, notwithstanding the fact that the defendant’s accomplices, who pleaded guilty to lesser crimes, received lesser sentences. Bracken, J. P., Kunzeman, Kooper and Balletta, JJ., concur.