Index: pym/_emerge/depgraph.py
===================================================================
--- pym/_emerge/depgraph.py	(revision 13744)
+++ pym/_emerge/depgraph.py	(working copy)
@@ -2091,6 +2091,11 @@
 				break
 
 		if len(matched_packages) > 1:
+			if "--avoid-update" in self.myopts:
+				for pkg in matched_packages:
+					if pkg.installed:
+						return pkg, existing_node
+			
 			bestmatch = portage.best(
 				[pkg.cpv for pkg in matched_packages])
 			matched_packages = [pkg for pkg in matched_packages \
Index: pym/_emerge/main.py
===================================================================
--- pym/_emerge/main.py	(revision 13744)
+++ pym/_emerge/main.py	(working copy)
@@ -65,6 +65,7 @@
 "--searchdesc",   "--selective",
 "--skipfirst",
 "--tree",
+"--avoid-update",
 "--update",
 "--usepkg",       "--usepkgonly",
 "--verbose",
@@ -1060,6 +1061,10 @@
 			noiselevel=-1)
 		return 1
 
+	if ("--avoid-update" in myopts) and ("--update" in myopts):
+		writemsg("!!! confilcting options given: --update and --avoid-update\n", noiselevel=-1)
+		return 1
+
 	if settings.get("PORTAGE_DEBUG", "") == "1":
 		spinner.update = spinner.update_quiet
 		portage.debug=1
Index: pym/_emerge/help.py
===================================================================
--- pym/_emerge/help.py	(revision 13744)
+++ pym/_emerge/help.py	(working copy)
@@ -235,6 +235,14 @@
 		print "              to the prompt, so an accidental press of the \"Enter\" key at any"
 		print "              time prior to the prompt will be interpreted as a choice!"
 		print
+		print "       "+green("--avoid-update")
+		print "              Tries to prevent package updates. This may not always be possible"
+		print "              since new packages or new dependencies due to use flag changes may"
+		print "              require a newer version of an installed package. Furthermore this"
+		print "              option may lead to slot conflicts (Multiple package instances within"
+		print "              a single package slot have been pulled into the dependency graph)."
+		print "              It is not possible to use this option in such a case."
+		print
 		print "       "+green("--buildpkg")+" ("+green("-b")+" short option)"
 		desc = "Tells emerge to build binary packages for all ebuilds processed in" + \
 			" addition to actually merging the packages. Useful for maintainers" + \
Index: man/emerge.1
===================================================================
--- man/emerge.1	(revision 13744)
+++ man/emerge.1	(working copy)
@@ -90,6 +90,13 @@
 to the \fBworld\fR file at the end, so that they are considered for
 later updating.
 .TP
+.BR "\-\-avoid\-update "
+Tries to prevent package updates. This may not always be possible since new 
+packages or new dependencies due to use flag changes may require a newer version 
+of an installed package. Furthermore this option may lead to slot conflicts 
+(Multiple package instances within a single package slot have been pulled 
+into the dependency graph). It is not possible to use this option in such a case.
+.TP
 .BR "\-\-clean " (\fB\-c\fR)
 Cleans up the system by examining the installed packages and removing older
 packages.  This is accomplished by looking at each installed package and separating
@@ -364,6 +371,9 @@
 
 USE flags may be toggled by your profile as well as your USE and package.use
 settings.
+
+\fB\-\-avoid\-update\fR may prevent updates of installed packages without 
+use flag changes. Note that \fB\-\-avoid-\update\fR may lead to slot conflicts.
 .TP
 .BR "\-\-noconfmem"
 Causes portage to disregard merge records indicating that a config file