Petitioner, whose petition for habeas corpus was denied by the court without taking evidence, seeks a certificate of probable cause to appeal. He shows the following. He was convicted on his plea of guilty in the state court of the crime of armed robbery and was sentenced to a term of 9 to 12 years. He sought review of the sentence by the Appellate Division of the Superior Court under Mass.G.L. c. 278, § 28A et seq., Pursuant to the provisions of § 28B the court, after a hearing at which defendant was represented by counsel, ordered the sentence increased by substituting a sentence of 12 to 15 years. This sentence was thereafter imposed. At the time of the imposition no counsel representing the defendant was present. It is of this fact that he complains.

Defendant does not assert any constitutional objection to the incease in sentence. In this he is correct. Walsh v. Commonwealth, 1970, Mass., 260 N.E.2d 911; Hicks v. Commonwealth, 1962, 345 Mass. 89, 185 N.E.2d 739, cert. denied 374 U.S. 839, 83 S.Ct. 1891, 10 L.Ed.2d 1060; cf. Lemieux v. Robbins, 1 Cir., 1969, 414 F.2d 353, cert. denied 397 U.S. 1017, 90 S.Ct. 1247, 25 L.Ed.2d 432. Nor does he claim the sentence was otherwise unlawful.

It was, of course, necessary that defendant be represented at the hearing on the appeal, unless he waived such. Petition of Croteau, 1968, 353 Mass. 736, 234 N.E.2d 737; see Mempa v. Rhay, 1967, 389 U.S. 128, 88 S.Ct. 254, 19 L.Ed.2d 336. He was so represented. The issue is thus the narrow one, whether, once the court had made the determination, defendant was obliged to be represented when the sentence was actually imposed. The district court ruled that this was not a “critical stage in the criminal prosecution” because no rights could be lost, and the presence of counsel could not have enabled him to save rights which might have been prejudiced for want of assistance. We are entirely unable to think of any reason why the defendant was prejudiced. Cf., Vitoratos v. Maxwell, 6 Cir., 1965, 351 F.2d 217, cert. denied 383 U.S. 105, 86 S.Ct. 718, 15 L.Ed.2d 618. Defendant could not even have had the benefit of counsel’s advice with regard to a prompt appeal, as no appeal lay from the increase in sentence. If, conceivably, defendant had some extraordinary rights, they could be pursued only by writ of error, for the filing of which he had six years.

The request for a certificate of probable cause to appeal is denied.